Activity

Filter

Cancel
Date Panel Item Activity
14 actions
Intellectual disability - microarray and sequencing v3.1519 PHF6 Ivone Leong Tag Q4_21_MOI was removed from gene: PHF6.
Intellectual disability - microarray and sequencing v3.1519 PHF6 Sarah Leigh commented on gene: PHF6
Intellectual disability - microarray and sequencing v3.1519 PHF6 Ivone Leong Source NHS GMS was added to PHF6.
Mode of inheritance for gene PHF6 was changed from X-LINKED: hemizygous mutation in males, biallelic mutations in females to X-LINKED: hemizygous mutation in males, monoallelic mutations in females may cause disease (may be less severe, later onset than males)
Intellectual disability - microarray and sequencing v3.1475 PHF6 Ivone Leong reviewed gene: PHF6: Rating: ; Mode of pathogenicity: None; Publications: 24092917, 25099957; Phenotypes: ; Mode of inheritance: X-LINKED: hemizygous mutation in males, monoallelic mutations in females may cause disease (may be less severe, later onset than males)
Intellectual disability - microarray and sequencing v3.1475 PHF6 Ivone Leong Phenotypes for gene: PHF6 were changed from Borjeson-Forssman-Lehmann syndrome, 301900; BOERJESON-FORSSMAN-LEHMANN SYNDROME (BFLS) to Borjeson-Forssman-Lehmann syndrome, OMIM:301900
Intellectual disability - microarray and sequencing v3.1474 PHF6 Ivone Leong Publications for gene: PHF6 were set to
Intellectual disability - microarray and sequencing v3.1473 PHF6 Ivone Leong Tag Q4_21_MOI tag was added to gene: PHF6.
Intellectual disability - microarray and sequencing v2.1135 SNX27 Konstantinos Varvagiannis gene: SNX27 was added
gene: SNX27 was added to Intellectual disability. Sources: Literature
Mode of inheritance for gene: SNX27 was set to BIALLELIC, autosomal or pseudoautosomal
Publications for gene: SNX27 were set to 25894286; 31721175; 21300787; 23524343
Phenotypes for gene: SNX27 were set to Generalized hypotonia; Global developmental delay; Intellectual disability; Seizures
Penetrance for gene: SNX27 were set to Complete
Review for gene: SNX27 was set to GREEN
gene: SNX27 was marked as current diagnostic
Added comment: Evidence from 2 publications suggests that DD, ID and seizures are part of the phenotype of individuals with biallelic SNX27 pathogenic variants :
---------
Damseh, Danson et al (2015 - PMID: 25894286) first reported on a consanguineous family with 4 affected sibs, homozygous for an SNX27 pathogenic variant. Features incl. hypotonia soon after birth, failure to thrive, severely delayed psychomotor development with no milestone acquisition, occurrence of myoclonic seizures with 3 individuals deceased early. Exome sequencing in one revealed a few candidate variants, with an SNX27 frameshift one [NM_030918.6:c.515_516del - p.(His172Argfs*6) / absent from ExAC] being the only retained following Sanger segregation studies. Using fibroblasts from an affected individual, Western blot with an antibody which would also bind prior to the truncation site, was consistent with dramatically reduced/absent SNX27 truncated mutant protein. Protein levels of VPS35, a component of the retromer responsible for direct cargo binding (not mediated by a cargo adaptor as SNX27), were normal.
---------
Parente et al (2019 - PMID: 31721175) reported on a 13-year-old male with motor and language delay, ADHD, ID (kindergarten academic level at the age of 13) and seizures with onset at the age of 9 years (GTC, with abnormal EEG and postical SV tachycardia). Variable physical findings were reported. White matter hyperintesities were noted upon initial brain MRI (but were less marked in subsequent ones). Initial genetic testing (Alexander's disease, CMA, FMR1) was normal. Exome revealed compound heterozygosity for 2 SNX27 variants (NM_030918.5/NM_001330723.1 both apply c.510C>G - p.Tyr170* and c.1295G>A - p.Cys432Tyr) each inherited from healthy carrier parents. There were no other potentially causative variants. A parental history of - isolated - late onset seizures was reported (so this individual may not be considered for the seizure phenotype here).

The authors also reported on a further 31-year old affected male. This individual had infantile hypotonia, poor eye contact with subsequent significant DD, seizures (febrile/afebrile T-C with onset at the age of 14m) and ID estimated in the severe range. Variable - though somewhat different - physical findings were reported. Initial work-up included basic metabolic testing, standard karyotype, FISH for 15q11 and subtelomeric regions and PHF6 genetic testing - all normal. Exome (and subsequent Sanger confirmation/parental studies) revealed compound heterozygosity for a missense and a frameshift variant (c.989G>A / p.Arg330His and c.782dupT / p.Leu262Profs*6 same in NM_001330723.1, NM_030918.6).
---------
SNX27 encodes sorting nexin 27, a cargo adaptor for the retromer. The latter is a multi-protein complex essential for regulating the retrieval and recycling of transmembrane cargos from endosomes to the trans-Golgi network or the plasma membrane [Lucas et al 2016 - PMID: 27889239 / McNally et al 2018 - PMID: 30072228].

As summarized by Parente et al, the encoded protein by regulating composition of the cell surface influences several processes eg. neuronal excitability, synaptic plasticity, Wnt signaling etc. It has been shown to interact with surface receptors and their ligands including GIRK channels, 5-HT4, ionotropic glutamate receptors (incl. NMDA- and AMPA-type receptors) and mGluR5 [several refs. provided].

Knockout of Snx27 in mice resulted in embryonic lethality (16% hmz of the 25% expected), severe postnatal growth retardation and death within the first 3 weeks. Snx27(+/-) mice have normal neuroanatomy but exhibit cognitive deficits (in learning and memory) and defects in synaptic function/plasticity with reduced amounts of NMDA and AMPA receptors (Cai et al - PMID: 21300787, Wang et al - PMID: 23524343).
---------
The gene is included in gene panels for ID offered by some diagnostic laboratories (eg. GeneDx) and a current primary ID gene in SysID. There is no associated phenotype in OMIM/G2P.
Sources: Literature
Intellectual disability - microarray and sequencing v2.938 TRPM3 Konstantinos Varvagiannis changed review comment from: Dyment et al. (2019 - https://doi.org/10.1038/s41431-019-0462-x) report on 7 unrelated individuals with a recurrent de novo TRPM3 missense variant [NM_020952.4:c.2509G>A - NP_066003.3:p.(Val837Met)] as well as an additional individual with a further de novo missense variant [c.2810C>A or p.(Pro937Gln) - same ref. sequences].

Overlapping features included hypotonia (7/8 - in one case mixed tone abnormality), DD/ID (8/8 - all individuals at appropriate age - degree relevant), EEG-confirmed epilepsy (7/8). Autism-like features were observed in 4 (out of 6 for whom this information was reported). Other features were noted in a minority (or were private to certain) of these individuals.

Different clinical types of seizures were reported incl. absence, generalized-toni-clonic, infantile spasms as well as subclinical ones. Onset was in infancy or early childhood.

In all individuals the variant was found following trio exome sequencing.

The first variant fulfilled ACMG criteria to be classified as pathogenic due to it's de novo occurrence, prevalence in affected individuals (>=6 affected individuals and in the same time) absence from population databases, in silico predictions in favour of pathogenicity (PS2, PS4_Moderate, PM2, PP3).

The Pro937Gln variant is however classified as a VUS. The subject harboring this variant had an additional de novo variant in another gene (DDB1) not associated with any phenotype, to date.

Several other genetic causes had previously been ruled out for most individuals by other investigations : aCGH was normal in all, FMR1 testing in 6 subjects, genes (PHF6, MECP2, MCT8) or smaller panels for ID (the latter in 3 subjects), mtDNA or testing of nuclear genes for mitochondrial disorders, etc.

TRPM3 encodes transient receptor potential (TRP) cation channel, subfamily M, member 3. TRP channels are a superfamily of gated cation channels sensitive to various physical or chemical stimuli (Clapham 2003 - PMID: 14654832 cited) eg. temperature or pain.

The gene is highly expressed in the brain in humans and other vertebrates (Grimm et al. 2003 - PMID : 12672799 and GTEx - https://gtexportal.org/home/gene/TRPM3).

Animal models : In rat brain, expression is initially restricted to neurons but later - as myelination progresses - shifts to oligodendrocytes (cited : Hoffmann et al. 2010 - PMID: 20163522). Most subjects had normal brain MRI appart from one individual with nonspecific white matter hyperintensities and another with possible mild cerebral volume loss. Trpm3 -/- mice show attenuated nocifensive behavior after heat or dermal injection of pregnenolone sulfate. Heat or pain insensitivity was reported only for 2 individuals.

Functional studies were not carried out, although some hypotheses are proposed following in silico modeling of the TRPM3 variants using an available structure for TRPM7.

As discussed by Dyment et al., happloinsufficiency appears to be unlikely given the presence of LoF variants in ExAC/gnomAD (pLI of 0), some intragenic copy number variants in DGV. In addition, pathogenicity of deletions spanning only TRPM3 or additional proximal genes was not evident in 2 cases:
- In the first case a exon 1-9 deletion was found in 2 brothers with Becker muscular dystrophy due to DMD intragenic duplication and autism/cognitive impairment though the TRPM3 deletion was found also in unaffected family members. The deletion was also found in unaffected relatives. A multiple hit hypothesis was hypothesized for this family. [Pagnamenta et al. 2011 - PMID: 21484199]
- Kuniba et al. [2009 - PMID: 19343044] reported a 1.27-Mb deletion spanning TRPM3, KLF9, SMC5 and MAMDC2 in a patient with Kabuki syndrome working diagnosis. Segregation studies were however not possible. At the time, the molecular etiology of Kabuki syndrome (KMT2D/KDM6A) was not known.
-----
TRPM3 is not associated with any phenotype in OMIM or G2P.
This gene is included in panels for ID offered by some diagnostic laboratories (eg. GeneDx participating in the above study).
-----
As a result, TRPM3 seems to fulfill criteria for inclusion in the ID/epilepsy panels probably as green (# of individuals, degree of ID relevant, EEG-confirmed epilepsy) or amber (if further functional evidence would be required).

[Please consider eligibility for inclusion in other possibly relevant panels eg. autism, etc].
Sources: Literature; to: Dyment et al. (2019 - https://doi.org/10.1038/s41431-019-0462-x) report on 7 unrelated individuals with a recurrent de novo TRPM3 missense variant [NM_020952.4:c.2509G>A - NP_066003.3:p.(Val837Met)] as well as an additional individual with a further de novo missense variant [c.2810C>A or p.(Pro937Gln) - same ref. sequences].

Overlapping features included hypotonia (7/8 - in one case mixed tone abnormality), DD/ID (8/8 - all individuals at appropriate age - degree relevant), EEG-confirmed epilepsy (7/8). Autism-like features were observed in 4 (out of 6 for whom this information was reported). Other features were noted in a minority (or were private to certain) of these individuals.

Different clinical types of seizures were reported incl. absence, generalized-toni-clonic, infantile spasms as well as subclinical ones. Onset was in infancy or early childhood.

In all individuals the variant was found following trio exome sequencing.

The first variant fulfilled ACMG criteria to be classified as pathogenic due to it's de novo occurrence, prevalence in affected individuals (>=6 affected individuals and in the same time) absence from population databases, in silico predictions in favour of pathogenicity (PS2, PS4_Moderate, PM2, PP3).

The Pro937Gln variant is however also present once in gnomAD (1/251370 alleles or AF:3.98e-6) and is classified as VUS according to the ACMG criteria. The subject harboring this variant had an additional de novo variant in another gene (DDB1) not associated with any phenotype, to date.

Several other genetic causes had previously been ruled out for most individuals by other investigations : aCGH was normal in all, FMR1 testing in 6 subjects, genes (PHF6, MECP2, MCT8) or smaller panels for ID (the latter in 3 subjects), mtDNA or testing of nuclear genes for mitochondrial disorders, etc.

TRPM3 encodes transient receptor potential (TRP) cation channel, subfamily M, member 3. TRP channels are a superfamily of gated cation channels sensitive to various physical or chemical stimuli (Clapham 2003 - PMID: 14654832 cited) eg. temperature or pain.

The gene is highly expressed in the brain in humans and other vertebrates (Grimm et al. 2003 - PMID : 12672799 and GTEx - https://gtexportal.org/home/gene/TRPM3).

Animal models : In rat brain, expression is initially restricted to neurons but later - as myelination progresses - shifts to oligodendrocytes (cited : Hoffmann et al. 2010 - PMID: 20163522). Most subjects had normal brain MRI appart from one individual with nonspecific white matter hyperintensities and another with possible mild cerebral volume loss. Trpm3 -/- mice show attenuated nocifensive behavior after heat or dermal injection of pregnenolone sulfate. Heat or pain insensitivity was reported only for 2 individuals.

Functional studies were not carried out, although some hypotheses are proposed following in silico modeling of the TRPM3 variants using an available structure for TRPM7.

As discussed by Dyment et al., happloinsufficiency appears to be unlikely given the presence of LoF variants in ExAC/gnomAD (pLI of 0), some intragenic copy number variants in DGV. In addition, pathogenicity of deletions spanning only TRPM3 or additional proximal genes was not evident in 2 cases:
- In the first case a exon 1-9 deletion was found in 2 brothers with Becker muscular dystrophy due to DMD intragenic duplication and autism/cognitive impairment though the TRPM3 deletion was found also in unaffected family members. The deletion was also found in unaffected relatives. A multiple hit hypothesis was hypothesized for this family. [Pagnamenta et al. 2011 - PMID: 21484199]
- Kuniba et al. [2009 - PMID: 19343044] reported a 1.27-Mb deletion spanning TRPM3, KLF9, SMC5 and MAMDC2 in a patient with Kabuki syndrome working diagnosis. Segregation studies were however not possible. At the time, the molecular etiology of Kabuki syndrome (KMT2D/KDM6A) was not known.
-----
TRPM3 is not associated with any phenotype in OMIM or G2P.
This gene is included in panels for ID offered by some diagnostic laboratories (eg. GeneDx participating in the above study).
-----
As a result, TRPM3 seems to fulfill criteria for inclusion in the ID/epilepsy panels probably as green (# of individuals, degree of ID relevant, EEG-confirmed epilepsy) or amber (if further functional evidence would be required).

[Please consider eligibility for inclusion in other possibly relevant panels eg. autism, etc].
Sources: Literature
Intellectual disability - microarray and sequencing v2.938 TRPM3 Konstantinos Varvagiannis gene: TRPM3 was added
gene: TRPM3 was added to Intellectual disability. Sources: Literature
Mode of inheritance for gene: TRPM3 was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown
Publications for gene: TRPM3 were set to doi.org/10.1038/s41431-019-0462-x
Phenotypes for gene: TRPM3 were set to Generalized hypotonia; Global developmental delay; Intellectual disability; Seizures; Autistic behavior
Penetrance for gene: TRPM3 were set to unknown
Mode of pathogenicity for gene: TRPM3 was set to Loss-of-function variants (as defined in pop up message) DO NOT cause this phenotype - please provide details in the comments
Review for gene: TRPM3 was set to GREEN
gene: TRPM3 was marked as current diagnostic
Added comment: Dyment et al. (2019 - https://doi.org/10.1038/s41431-019-0462-x) report on 7 unrelated individuals with a recurrent de novo TRPM3 missense variant [NM_020952.4:c.2509G>A - NP_066003.3:p.(Val837Met)] as well as an additional individual with a further de novo missense variant [c.2810C>A or p.(Pro937Gln) - same ref. sequences].

Overlapping features included hypotonia (7/8 - in one case mixed tone abnormality), DD/ID (8/8 - all individuals at appropriate age - degree relevant), EEG-confirmed epilepsy (7/8). Autism-like features were observed in 4 (out of 6 for whom this information was reported). Other features were noted in a minority (or were private to certain) of these individuals.

Different clinical types of seizures were reported incl. absence, generalized-toni-clonic, infantile spasms as well as subclinical ones. Onset was in infancy or early childhood.

In all individuals the variant was found following trio exome sequencing.

The first variant fulfilled ACMG criteria to be classified as pathogenic due to it's de novo occurrence, prevalence in affected individuals (>=6 affected individuals and in the same time) absence from population databases, in silico predictions in favour of pathogenicity (PS2, PS4_Moderate, PM2, PP3).

The Pro937Gln variant is however classified as a VUS. The subject harboring this variant had an additional de novo variant in another gene (DDB1) not associated with any phenotype, to date.

Several other genetic causes had previously been ruled out for most individuals by other investigations : aCGH was normal in all, FMR1 testing in 6 subjects, genes (PHF6, MECP2, MCT8) or smaller panels for ID (the latter in 3 subjects), mtDNA or testing of nuclear genes for mitochondrial disorders, etc.

TRPM3 encodes transient receptor potential (TRP) cation channel, subfamily M, member 3. TRP channels are a superfamily of gated cation channels sensitive to various physical or chemical stimuli (Clapham 2003 - PMID: 14654832 cited) eg. temperature or pain.

The gene is highly expressed in the brain in humans and other vertebrates (Grimm et al. 2003 - PMID : 12672799 and GTEx - https://gtexportal.org/home/gene/TRPM3).

Animal models : In rat brain, expression is initially restricted to neurons but later - as myelination progresses - shifts to oligodendrocytes (cited : Hoffmann et al. 2010 - PMID: 20163522). Most subjects had normal brain MRI appart from one individual with nonspecific white matter hyperintensities and another with possible mild cerebral volume loss. Trpm3 -/- mice show attenuated nocifensive behavior after heat or dermal injection of pregnenolone sulfate. Heat or pain insensitivity was reported only for 2 individuals.

Functional studies were not carried out, although some hypotheses are proposed following in silico modeling of the TRPM3 variants using an available structure for TRPM7.

As discussed by Dyment et al., happloinsufficiency appears to be unlikely given the presence of LoF variants in ExAC/gnomAD (pLI of 0), some intragenic copy number variants in DGV. In addition, pathogenicity of deletions spanning only TRPM3 or additional proximal genes was not evident in 2 cases:
- In the first case a exon 1-9 deletion was found in 2 brothers with Becker muscular dystrophy due to DMD intragenic duplication and autism/cognitive impairment though the TRPM3 deletion was found also in unaffected family members. The deletion was also found in unaffected relatives. A multiple hit hypothesis was hypothesized for this family. [Pagnamenta et al. 2011 - PMID: 21484199]
- Kuniba et al. [2009 - PMID: 19343044] reported a 1.27-Mb deletion spanning TRPM3, KLF9, SMC5 and MAMDC2 in a patient with Kabuki syndrome working diagnosis. Segregation studies were however not possible. At the time, the molecular etiology of Kabuki syndrome (KMT2D/KDM6A) was not known.
-----
TRPM3 is not associated with any phenotype in OMIM or G2P.
This gene is included in panels for ID offered by some diagnostic laboratories (eg. GeneDx participating in the above study).
-----
As a result, TRPM3 seems to fulfill criteria for inclusion in the ID/epilepsy panels probably as green (# of individuals, degree of ID relevant, EEG-confirmed epilepsy) or amber (if further functional evidence would be required).

[Please consider eligibility for inclusion in other possibly relevant panels eg. autism, etc].
Sources: Literature
Intellectual disability - microarray and sequencing v2.468 PHF6 Louise Daugherty Source Victorian Clinical Genetics Services was added to PHF6.
Intellectual disability - microarray and sequencing PHF6 BRIDGE consortium edited their review of PHF6
Intellectual disability - microarray and sequencing PHF6 BRIDGE consortium edited their review of PHF6
Intellectual disability - microarray and sequencing PHF6 BRIDGE consortium reviewed PHF6