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| Intellectual disability - microarray and sequencing v5.196 | KDM6B | Sarah Leigh Phenotypes for gene: KDM6B were changed from Neurodevelopmental disorder with coarse facies and mild distal skeletal abnormalities, 618505 to Neurodevelopmental disorder with coarse facies and mild distal skeletal abnormalities, OMIM:618505; neurodevelopmental disorder with coarse facies and mild distal skeletal abnormalities, MONDO:0032790 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability - microarray and sequencing v4.126 |
Arina Puzriakova Panel name changed from Intellectual disability to Intellectual disability - microarray and sequencing List of related panels changed from Coarse facial features including Coffin-Siris-like disorders; ID; Moderate; severe or profound intellectual disability; Schizophrenia plus additional features; Intellectual disability - microarray; fragile X and sequencing; R29 to Coarse facial features including Coffin-Siris-like disorders; ID; Moderate; severe or profound intellectual disability; Schizophrenia plus additional features; Intellectual disability - microarray; fragile X and sequencing; Intellectual disability; R29 |
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| Intellectual disability - microarray and sequencing v3.1659 | TFE3 | Arina Puzriakova Phenotypes for gene: TFE3 were changed from TFE3-related intellectual disability with pigmentary mosaicism to Intellectual developmental disorder, X-linked, syndromic, with pigmentary mosaicism and coarse facies, OMIM:301066 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability - microarray and sequencing v3.1561 | DPH5 |
Konstantinos Varvagiannis gene: DPH5 was added gene: DPH5 was added to Intellectual disability. Sources: Literature Mode of inheritance for gene: DPH5 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: DPH5 were set to 35482014 Phenotypes for gene: DPH5 were set to Abnormality of prenatal development or birth; Neonatal hypotonia; Global developmental delay; Intellectual disability; Seizures; Abnormality of the cardiovascular system; Abnormality of the globe; Feeding difficulties; Short stature; Abnormality of head or neck Penetrance for gene: DPH5 were set to unknown Review for gene: DPH5 was set to AMBER Added comment: Shankar et al (2022 - PMID: 35482014) present evidence for a diphthamide-deficiency syndrome due to biallelic DPH5 pathogenic variants. As the authors summarize, DPH5 encodes a methyltransferase critical to the biosynthesis of diphthamide. Diphthamide is a post translationally modified histidine residue found in eukaryotic elongation factor 2 (eEF2). eEF2 is essential for mRNA translation and protein synthesis. The role of diphthamide is not clear, although it serves as a target for ADP-ribosylation, the latter resulting in inactivation of the eEF2 (inhibition of its translocation activity) and arrest of protein synthesis. Biosynthesis of diphthamide is complex involving multiple components (DPH1-DPH7) and the methylating co-factor S-adenosyl methionine, with 2 diphthamide-deficiency disorders due to biallelic DPH1 or DPH2 pathogenic variants and a NDD phenotype reported to date. The authors describe a phenotypic spectrum associated with biallelic DPH5 variants ranging from a prenatally lethal presentation to profound neurodevelopmental disorder. Details are provided on 5 individuals from 3 unrelated families. While one subject died at the age of few days due to multisystem complications, the phenotype appeared to be relatively consistent with prenatal findings (decreased fetal movements in 2 from 2 families, polyhydramnios in 2 from 2 families), hypotonia, global DD and ID (4/4 from 2 families - profound in 3), seizures (3/5 from 2 families - abnormal EEG in 4/4), cardiovascular findings (5/5, MVP and regurgitation in 2 from Fam1 || aortic dilatation in 2 sibs from Fam2 || VSD, ASD and hypopl. PA, pericardial effusion in 5th), GI issues (5/5, poor feeding in 4), short stature (4/4). Ocular findings were reported in 3/4 (gray sclerae in 2, ocular melanocytosis in 2). The authors describe some common craniofacial findings incl. broad/prominent forehead (5/5), sparse eyebrows (4/5), downturned corners of mouth or triangular chin (each in 3/5). WES/WGS revealed biallelic DPH5 variants in all affected individuals, namely: homozygosity for a missense variant in 2 sibs (NM_001077394.2:c.779A>G/p.His260Arg). Homozygosity for c.521dupA/p.Asn174LysTer10 for the individual deceased in the neonatal period (for this family there was significant history of spontaneous miscarriages/stillbirth/neonatal death). Two sibs born to non-consanguineous parents were compound htz for a stopgain and a missense SNV (c.619C>T/p.Arg207*, c.329A>G/p.Asn110Ser). In silico modeling revealed that the pLoF variants, not predicted to lead to NMD, likely remove the domain for interaction with eEF2 while the missense ones also affected interaction with eEF2. In recombinant MCF7 breast cancer cell line-derived DPH5-knockouts, transfected with recombinant expr. plasmids encoding wt or the 4 variants, the 2 truncating variants were shown to affect ADP-ribosylation of eEF2's diphthamide (total lack / minimal enzymatic activity for Arg207* and Asn174Lysfs respectively). Asn110Ser and His260Arg had residual activities which was thought to be explained by high expression levels compensating partial inactivation (given the multicopy plasmid-driven expression). ADP-ribosylation assays in S. cerevisiae demonstrated loss of function for the 2 truncating variants. Although the 2 missense variants retained sufficient activity to produce diphthamide (assayed through toxin induced ADP-ribosylation of eEF2), more sensitive assays indicated that diphthamide synthesis was also partially compromised for both variants. Generation of a knockin mouse model for His260Arg, appeared to recapitulate the human phenotypes with craniofacial, ophthalmologic, cardiac and visceral abnormalities and hmz mice being subviable. A single homozygous liveborn mouse had low birthweight, FTT, craniofacial dysmorphology, polydactyly, abnormal grooming behavior and early death. Few heterozygous embryos had craniofacial features, decreased body weight, reduced neuromuscular function without other abnormalities, either due to their inbred background or in the context of milder phenotype of heterozygosity in mice. DPH5 is ubiquitously expressed in all human tissues. The gene has a pLI of 0 and LOEUF score of 0.77 (0.48-1.27) in gnomAD. The authors refer to unpublished data, noting that complete absence of DPH5 is incompatible with life with embryonic lethality of a Dph5(ko/ko) line. The phenotype bears similarities to DPH1- and DPH2- related NDDs (both AR / green and amber respectively in ID panel) and appears to be more severe compared to the phenotype of de novo EEF2 variants (cited PMID: 33355653). Please consider inclusion in the ID panel with amber (4 individuals from 2 families with ID) / green rating (rather consistent phenotype in 3 families probably representing a continuous spectrum, variant studies, mouse model, similarities with diphthamide-deficiency syndromes). Also consider amber rating in the epilepsy panel (3 individuals from 2 families reported). The gene may be also relevant in other gene panels e.g. for congenital heart disease, short stature, etc (not added). Sources: Literature |
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| Intellectual disability - microarray and sequencing v3.1262 | ZNF699 |
Zornitza Stark gene: ZNF699 was added gene: ZNF699 was added to Intellectual disability. Sources: Literature Mode of inheritance for gene: ZNF699 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: ZNF699 were set to 33875846 Phenotypes for gene: ZNF699 were set to DEGCAGS syndrome, MIM# 619488 Review for gene: ZNF699 was set to GREEN Added comment: DEGCAGS syndrome is a neurodevelopmental disorder characterized by global developmental delay, coarse and dysmorphic facial features, and poor growth and feeding apparent from infancy. Affected individuals have variable systemic manifestations often with significant structural defects of the cardiovascular, genitourinary, gastrointestinal, and/or skeletal systems. Additional features may include sensorineural hearing loss, hypotonia, anaemia or pancytopaenia, and immunodeficiency with recurrent infections. 12 unrelated families reported, 5 different homozygous frameshift variants. Sources: Literature |
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| Intellectual disability - microarray and sequencing v3.1103 | DPH1 | Arina Puzriakova Phenotypes for gene: DPH1 were changed from Developmental delay with short stature, dysmorphic features, and sparse hair, 616901 to Developmental delay with short stature, dysmorphic facial features, and sparse hair, OMIM:616901 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability - microarray and sequencing v3.740 | ABCC9 |
Arina Puzriakova changed review comment from: Comment on list classification: Intellectual impairment as been reported in individuals with loss-of-function variants and a percentage of those with gain-of-function variants. However, this is less prominent than other features of the disease presentation (e.g. cardiac, skeletal defects) and often ID is perhaps too mild. Therefore, ABCC9 will be flagged for review by the GMS team with regards to phenotypic fit for this panel and determine whether it should be demoted from Green to Amber (added for-review tag).; to: Comment on list classification: Intellectual impairment has been reported in individuals with loss-of-function variants and a percentage of those with gain-of-function variants. ID is typically mild, however it is plausible that patients may still be tested for this panel, particularly if recruited under Coffin-Siris-like coarse facial features which can be associated with this gene. Therefore, maintaining Green gene rating. Comment on mode of inheritance: Leaving MOI as Monoallelic as only 2 families with the same biallelic variant (possible founder variant) reported to date (PMID:31575858), and patients with biallelic variants would still be picked up by the Genomics England pipeline. |
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| Intellectual disability - microarray and sequencing v3.352 | KDM6B | Arina Puzriakova Phenotypes for gene: KDM6B were changed from Neurodevelopmental disorder with coarse facies and mild distal skeletal abnormalities, 618505 to Neurodevelopmental disorder with coarse facies and mild distal skeletal abnormalities, 618505 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability - microarray and sequencing v3.352 | KDM6B | Arina Puzriakova Phenotypes for gene: KDM6B were changed from AUTOSOMAL RECESSIVE MENTAL RETARDATION to Neurodevelopmental disorder with coarse facies and mild distal skeletal abnormalities, 618505 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability - microarray and sequencing v3.349 | KDM6B | Arina Puzriakova reviewed gene: KDM6B: Rating: GREEN; Mode of pathogenicity: None; Publications: 31124279; Phenotypes: Neurodevelopmental disorder with coarse facies and mild distal skeletal abnormalities, 618505; Mode of inheritance: MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability - microarray and sequencing v3.191 | KCNN3 |
Arina Puzriakova changed review comment from: Associated with phenotype in OMIM, and probable gene-disease association in G2P. Bauer et al. (2019) PMID: 31155282 - De novo heterozygous gain-of-function variants identified in three unrelated individuals with ZimmermannLaband syndrome. Mild-moderate ID was reported in a 46-year-old man, while developmental delay was noted for the other two patients: a 4.5-year-old (first words at 2.5 y; attends nursery) and 5.5-year-old girl (limited spoken language; attends school with a personal aide). Additional features include coarse face, gingival hyperplasia, and/or nail hypo- or aplasia. ; to: Associated with phenotype in OMIM, and probable gene-disease association in G2P. Bauer et al. (2019) PMID: 31155282 - De novo heterozygous gain-of-function variants identified in three unrelated individuals with ZimmermannLaband syndrome. Mild-moderate ID was reported in a 46-year-old man, while developmental delay was noted for the other two patients: a 4.5-year-old (first words at 2.5 y; attends nursery) and 5.5-year-old girl (limited spoken language; attends school with a personal aide). Additional features include coarse face, gingival hyperplasia, and/or nail hypo- or aplasia. |
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| Intellectual disability - microarray and sequencing v3.35 | CDC42BPB |
Konstantinos Varvagiannis gene: CDC42BPB was added gene: CDC42BPB was added to Intellectual disability. Sources: Literature Mode of inheritance for gene: CDC42BPB was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown Publications for gene: CDC42BPB were set to 32031333 Phenotypes for gene: CDC42BPB were set to Central hypotonia; Global developmental delay; Intellectual disability; Seizures; Autistic behavior; Behavioral abnormality Penetrance for gene: CDC42BPB were set to unknown Review for gene: CDC42BPB was set to GREEN Added comment: Chilton et al (2020 - PMID: 32031333) report on 14 individuals with missense and loss-of-function CDC42BPB variants. Features included hypotonia (8/11), DD (12/13 - the 14th was a fetus), ID (7/13), ASD (8/12), clinical seizures (in 3 - a 4th had abnormal EEG without seizures), behavioral abnormalities. Variable non-specific dysmorphic features were reported in some (sparse hair being the most frequent - 4/8). Additional features were observed in few (=<4) incl. cryptorchidism, ophthalmological issues, constipation, kidney abnormalities, micropenis, etc. All individuals had non-diagnostic prior genetic testing (incl. CMA, FMR1, MECP2, Angelman/Prader-Willi methylation studies, autism gene panel - suggesting relevance to the current panel) or metabolic testing. Variants were identified following clinical exome sequencing with Sanger confirmation. Most occurred as de novo events (11/14) while inheritance was not available for few (3/14). Missense variants did not display (particular) clustering. Almost all variants were absent from gnomAD and were predicted to be deleterious in silico (among others almost all had CADD scores >25). As the authors comment, CDC42BPB encodes myotonic dystrophy-related Cdc42-binding kinase β (MRCKβ) a serine/threonine protein kinase playing a role in regulation of cytoskeletal reorganization and cell migration in nonmuscle cells (through phosporylation of MLC2). Previous studies have demonstrated that it is ubiquitously expressed with prenatal brain expression. The gene appears to be intolerant to pLoF (pLI of 1) as well as to missense variants (Z-score of 3.66). CDC42BPB is a downstream effector of CDC42. Mutations of the latter cause Takenouchi-Kosaki syndrome with DD/ID and some further overlapping features (with CDC42BPB-associated phenotypes). Homozygous Cdc42bpb KO in mouse appears to be nonviable (MGI:2136459). Loss of gek in the eyes of Drosophila results in disrupted growth cone targeting to the lamina (gek is the fly CDC42BPB ortholog). Please consider inclusion with amber / green rating in the ID panel (>=4 relevant individuals / variants) and other panels (e.g. for epilepsy, ASD). Sources: Literature |
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| Intellectual disability - microarray and sequencing v3.0 | TFE3 | Konstantinos Varvagiannis reviewed gene: TFE3: Rating: GREEN; Mode of pathogenicity: Other; Publications: 30595499, 31833172, https://doi.org/10.1126/scisignal.aax0926; Phenotypes: Global developmental delay, Intellectual disability, Abnormality of skin pigmentation, Coarse facial features, Seizures; Mode of inheritance: Other | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability - microarray and sequencing v2.1143 |
Rebecca Foulger List of related panels changed from Coarse facial features including Coffin-Siris-like disorders; ID; Moderate; severe or profound intellectual disability; Schizophrenia plus additional features; Intellectual disability - microarray; fragile X and sequencing to Coarse facial features including Coffin-Siris-like disorders; ID; Moderate; severe or profound intellectual disability; Schizophrenia plus additional features; Intellectual disability - microarray; fragile X and sequencing; R29 Panel types changed to Rare Disease 100K; GMS Rare Disease Virtual; Component Of Super Panel; GMS signed-off |
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| Intellectual disability - microarray and sequencing v2.1022 | ARSE | Louise Daugherty Tag new-gene-name tag was added to gene: ARSE. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability - microarray and sequencing v2.1022 | ARSE | Louise Daugherty commented on gene: ARSE | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability - microarray and sequencing v2.978 | DPH1 |
Catherine Snow Source Expert Review Green was added to DPH1. Added phenotypes Developmental delay with short stature, dysmorphic features, and sparse hair, 616901 for gene: DPH1 Publications for gene DPH1 were changed from 25558065; 26220823; 29362492; 29410513 to 29362492; 29410513; 26220823; 25558065 Rating Changed from No List (delete) to Green List (high evidence) |
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| Intellectual disability - microarray and sequencing v2.953 | DEGS1 |
Konstantinos Varvagiannis gene: DEGS1 was added gene: DEGS1 was added to Intellectual disability. Sources: Literature Mode of inheritance for gene: DEGS1 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: DEGS1 were set to 30620337; 30620338; 31186544 Phenotypes for gene: DEGS1 were set to Leukodystrophy hypomyelinating 18, MIM 618404) Penetrance for gene: DEGS1 were set to Complete Review for gene: DEGS1 was set to GREEN Added comment: Several individuals with biallelic pathogenic DEGS1 variants have been reported to date, in the following studies : [1] Pant et al. 2019 (PMID: 30620337) : 19 patients from 13 unrelated families [2] Karsai et al. 2019 (PMID: 30620338) : 1 individual [3] Dolgin et al. 2019 (PMID: 31186544) : 4 individuals belonging to a large consanguineous kindred As summarized in the first article and OMIM, affected individuals may have very poor psychomotor development, dystonia, spasticity, seizures with hypomyelinating leukodystrophy upon brain imaging and/or progressive atrophy of corpus callosum, thalami and cerebellum. Although a severe form overall was reported for many individuals in the first study, variable severity (eg. mild to severe ID) was reported among individuals belonging to the same kindred in the report by Dolgin et al. DEGS1 encodes Δ4-dehydroceramide desaturase which catalyzes conversion of dihydroceramide (DhCer) to ceramide (Cer) in the de novo ceramide biosynthetic pathway. Ceramide is the central unit of all sphingolipids, which are components of cellular membranes and play key roles in several processes incl. cell differentiation, neuronal signaling and myelin sheath formation. Sphingolipid balance is important for the CNS as demonstrated in the case of lysosomal disorders (eg. Gaucher, Niemann Pick, Farber) one enzymatic step away from DEGS1. Variants of all types (missense, stopgain, frameshift) have been reported with the majority/almost all located in the fatty acid desaturase (FAD) domain. Extensive studies have been carried out and demonstrated: - impaired DEGS1 activity in patients' fibroblasts and muscle suggested by increased DhCer/Cer ratio and compatible broader biochemical effects (higher levels of dihydrosphingosine, dihydrosphingomyelins, etc. and lower levels of sphingosine, monohexosylceramides, etc). - increased ROS production in patient fibroblasts (similar to a Drosophila model of excess DhCer), - high expression of the gene in child and adult CNS tissues from control individuals (evaluated by RT-qPCR in Ref. 1). A previous study has suggested that DEGS1 expression is upregulated during the 4-9th week of human embryogenesis (PMID cited: 20430792) which may suggest an important role for neural system development. - decreased expression for some variants either evaluated at the mRNA (RT-qPCR) / protein level (by Western Blot) - In zebrafish loss of Degs1 resulted in increased DhCer/Cer ratio, locomotor disability and impaired myelination similar to the patients' phenotype. Fingolimod, a sphingosine analog inhibiting Cer synthase (one step prior to DEGS1 in the de novo ceramide biosynthesis pathway, and converting sphingosine to ceramide in the salvage pathway) reduced the DhCer/Cer imbalance, ameliorated the locomotor phenotype and increased the number of myelinating oligodendrocytes in zebrafish, while it reduced the ROS levels in patient fibroblasts. Previous animal models: Apart from the zebrafish model (Pant et al.), higher DhCer/Cer ratios have been shown in homozygous Degs1 -/- mice similar to what is also observed in D. melanogaster. As summarized in MGI (and the previous studies as well) "mice homozygous for a knock-out allele exhibit premature death, decreased to absent ceramide levels, decreased body weight, scaly skin, sparse hair, tremors, hematological and blood chemistry abnormalities, decreased bone mineral content and density and decreased liver function." (PMIDs cited: 17339025, 28507162). ---- The respective OMIM entry is Leukodystrophy, hypomyelinating, 18 (#618404). DEGS1 is not associated with any phenotype in G2P. ---- As a result, DEGS1 can be considered for inclusion in the ID and epilepsy panels probably as green (relevant phenotype, sufficient number of individuals, supportive expression and biochemical studies, animal models, etc). Sources: Literature |
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| Intellectual disability - microarray and sequencing v2.783 | Richard Scott List of related panels changed from Coarse facial features including Coffin-Siris-like disorders; ID; Moderate; severe or profound intellectual disability; Schizophrenia plus additional features; Intellectual disability – microarray; fragile X and sequencing to Coarse facial features including Coffin-Siris-like disorders; ID; Moderate; severe or profound intellectual disability; Schizophrenia plus additional features; Intellectual disability - microarray; fragile X and sequencing | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability - microarray and sequencing v2.717 | CCDC47 | Louise Daugherty commented on gene: CCDC47: Trichohepatoneurodevelopmental syndrome is a complex multisystem disorder characterized by woolly or coarse hair, liver dysfunction, pruritus, dysmorphic features, hypotonia, and severe global developmental delay (Morimoto el al., 2018) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability - microarray and sequencing v2.587 | Louise Daugherty List of related panels changed from Coarse facial features including Coffin-Siris-like disorders; ID; Moderate; severe or profound intellectual disability; Schizophrenia plus additional features; Intellectual disability – microarray; fragile X and sequencing; GMS R29 to Coarse facial features including Coffin-Siris-like disorders; ID; Moderate; severe or profound intellectual disability; Schizophrenia plus additional features; Intellectual disability – microarray; fragile X and sequencing | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability - microarray and sequencing v2.579 | PUS3 |
Konstantinos Varvagiannis gene: PUS3 was added gene: PUS3 was added to Intellectual disability. Sources: Literature,Radboud University Medical Center, Nijmegen Mode of inheritance for gene: PUS3 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: PUS3 were set to 27055666; 30308082 Phenotypes for gene: PUS3 were set to Global developmental delay; Intellectual disability; Microcephaly Penetrance for gene: PUS3 were set to Complete Review for gene: PUS3 was set to AMBER gene: PUS3 was marked as current diagnostic Added comment: PUS3 (Pseudouridylate synthase 3) is proposed as a gene related to ID in a recent publication on PUS7. Biallelic mutations in this gene are associated in OMIM with ?Mental retardation, autosomal recessive 55 (MIM 617051). PMID: 27055666 reports on 3 sisters from a consanguineous Saudi Arabian family with failure to thrive, DD/ID, microcephaly and some common (coarse) facial features. These individuals were homozygous for a stopgain mutation in the last exon of the gene. Pseudouridylation appeared to be defective (as has also been the case with other genes related to ID, eg. PUS7). PMID: 30308082 describes 1 individual born to consanguineous Palestinian parents, homozygous for a further LoF variant. Despite the localisation of this variant (again in the last exon of the gene) qPCR analyses were suggestive of degradation of the abnormal transcript possibly by NMD. The phenotype consisted of DD/ID and microcephaly. In a further publication (http://dx.doi.org/10.7124/bc.0008D6) Gulkovskyi et al. report on 2 siblings with ID, born to non-consanguineous Ukranian parents. Pathogenicity of the variant is disputed. [NM_031307.4:c.212A>G or p.(Tyr71Cys) is found in an apparent homozygous state in the sibs but was only found in their father. De novo occurence in the maternal allele is proposed although the possibility of microdeletion missed by aCGH or other plausible mechanisms are not considered. This variant has maximum pathogenicity scores in silico (not discussed) and has an allele frequency of 0.00006717 in gnomAD. The authors did not perform studies of pseudouridylation but examined for the presence of hypoproteinemia, observed in some disorders affecting this process). PUS3 is not associated with any phenotype in G2P but is associated with disease in OMIM. The gene is included in gene panels for ID offered by various diagnostic laboratories (including Radboudumc). PUS1 is included in the current panel as green and PUS7 has been suggested for inclusion. As a result, these gene can be considered for inclusion as amber (2 families) or green (given the supportive functional studies and/or the proposed role for the gene). Sources: Literature, Radboud University Medical Center, Nijmegen |
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| Intellectual disability - microarray and sequencing v2.576 | PPP1R21 |
Konstantinos Varvagiannis gene: PPP1R21 was added gene: PPP1R21 was added to Intellectual disability. Sources: Literature Mode of inheritance for gene: PPP1R21 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: PPP1R21 were set to 29808498; 28940097 Phenotypes for gene: PPP1R21 were set to Generalized hypotonia; Feeding difficulties; Profound global developmental delay; Abnormality of the face; Abnormality of vision; Abnormal heart morphology; Abnormality of the respiratory system; Hepatosplenomegaly Penetrance for gene: PPP1R21 were set to Complete Review for gene: PPP1R21 was set to GREEN Added comment: Biallelic pathogenic variants in PPP1R21 have been reported so far in 9 individuals from 7 unrelated families. All (7 different) variants reported to date are truncating. PMID: 29808498 is the first detailed clinical description on the related phenotype. 3 individuals from 3 families are reported. One of these individuals was previously included in a larger patient cohort (in PMID: 28940097). In a subsequent further publication, Rehman et al. (https://doi.org/10.1002/humu.23694) describe 6 additional patients from 4 unrelated consanguineous families. Again, these individuals were homozygous for truncating mutations. The authors summarize the findings in their patients as well as the previously reported ones. Common features included feeding difficulties, hypotonia with severe global DD and mildly coarsened facial features (all were observed in 9/9), visual anomalies (8/9), respiratory problems (7/9), cardiac anomalies (4/9) and hepato-/splenomegaly (3/7). Brain MRI anomalies were observed in the majority. DD was severe in all and ID (which is not explicitly mentioned) was evident from the clinical description of several individuals (eg. in PMID: 29808498). In total 7 loss-of-function variants have been reported. The authors in the first article, underscore the possibility of less severe phenotypes associated to biallelic missense variants (although none has been reported so far). Functional studies have shown great reduction (but not complete absence) of PPP1R21 mRNA levels in patient fibroblasts compared to controls. A role of PPP1R21 in the endosomal-lysosomal function is demonstrated in line with the presence of myelin figures in patient fibroblasts as well as some phenotypic similarities to neurometabolic/lysosomal storage disorders. Most variants reported in the most recent publication except one (NM_001135629.2:c.1607dupT) seem to affect all 3 PPP1R21 isoforms (which also seems to be the case for previously published variants). c.1607dupT appears to be the single truncating variant affecting 2 (of 3) isoforms. This variant was however shown to have severely reduced expression in fibroblasts upon qPCR, absent protein staining, and increase in myelin figures. The protein is expressed in embryonic mouse cortex. Overall, this gene can be considered for inclusion in this panel as green (or amber). Sources: Literature |
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| Intellectual disability - microarray and sequencing v2.556 | DPH1 |
Konstantinos Varvagiannis gene: DPH1 was added gene: DPH1 was added to Intellectual disability. Sources: Literature,Expert Review Mode of inheritance for gene: DPH1 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: DPH1 were set to 25558065; 26220823; 29362492; 29410513 Phenotypes for gene: DPH1 were set to Developmental delay with short stature, dysmorphic features, and sparse hair, 616901 Penetrance for gene: DPH1 were set to Complete Review for gene: DPH1 was set to GREEN gene: DPH1 was marked as current diagnostic Added comment: Biallelic mutations in DPH1 cause Developmental delay with short stature, dysmorphic features, and sparse hair, MIM 616901. Overall 11 patients from 6 different families have probably been reported in detail. DD/ID is a universal feature. In PMID 25558065, Alazami et al. identified 1 patient from the same consanguineous Saudi Arabian family (of 8 total similarly affected individuals) homozygous for the Leu234Pro (NM_001383.3:c.701T>C) variant. This individual was part of a large cohort of patients with neurogenetic disorders from consanguineous families. The phenotype is not described in detail. In PMID 26220823 Louks et al. report on 4 patients from 3 families belonging to the same genetic isolate from North America and provide details on 4 of the individuals identified by Alazami et al. The individuals identified in this study were homozygous for Met6Lys which was however predicted to be benign and tolerated (by PolyPhen2 and SIFT respectively) in silico. DD/ID, unusual skull shape, ectodermal anomalies were universal (8/8) with additional features including short stature (7/8), renal (4/6) or cardiac anomalies (3/8). Some facial features appeared to be common, too. Functional studies were not performed. However Dph1 pathogenic variants in mice result in restricted growth, craniofacial and developmental defects similar to the human phenotypes (PMIDs 14744934 and 24895408 are cited). PMIDs 29362492 and 29410513 report on 3 further patients with similar (as well as some additional) features including DD/ID. The individual in the first article was compound heterozygous for a missense (Leu164Pro) and a frameshift variant (c.289delG) while 2 sibs born to consanguineous parents in the second article were homozygous for a frameshift variant (c.1227delG). The phenotype appears to be consistent among all the published patients. DPH1 is included in gene panels for intellectual disability offered by different diagnostic laboratories. As a result, this gene can be considered for inclusion in this panel as green. Sources: Literature, Expert Review |
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| Intellectual disability - microarray and sequencing v2.542 | Ellen McDonagh List of related panels changed from Coarse facial features including Coffin-Siris-like disorders; ID; Moderate; severe or profound intellectual disability; Schizophrenia plus additional features to Coarse facial features including Coffin-Siris-like disorders; ID; Moderate; severe or profound intellectual disability; Schizophrenia plus additional features; Intellectual disability – microarray; fragile X and sequencing; GMS R29 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability - microarray and sequencing v2.534 | Ellen McDonagh List of related panels changed from Coarse facial features including Coffin-Siris-like disorders;ID;Moderate; severe or profound intellectual disability;Schizophrenia plus additional features to Coarse facial features including Coffin-Siris-like disorders; ID; Moderate; severe or profound intellectual disability; Schizophrenia plus additional features | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability - microarray and sequencing v2.533 | Ellen McDonagh List of related panels changed from Coarse facial features including Coffin-Siris-like disorders; ID;Moderate; severe or profound intellectual disability to Coarse facial features including Coffin-Siris-like disorders;ID;Moderate; severe or profound intellectual disability;Schizophrenia plus additional features | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability - microarray and sequencing | ARSE | BRIDGE consortium edited their review of ARSE | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability - microarray and sequencing | ARSE | BRIDGE consortium edited their review of ARSE | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability - microarray and sequencing | ARSE | BRIDGE consortium reviewed ARSE | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||