Intellectual disability - microarray and sequencing
Gene: LRRC32 Amber List (moderate evidence)I don't know
As reviewed by Hannah Knight, PMID:35656379 reported a homozygous LRRC32 variant (c.1354 G > A/ p.Glu452Lys) in a 15-year-old male with cleft palate, prenatal and postnatal severe growth retardation, global developmental delay, dysmorphic facial features and progressive vitreoretinopathy. This variant is different from the previously reported c.1630C>T/ p.Arg544Ter variant (suggested to be founder variant from haplotype analysis) that was reported in two unrelated families with global developmental delay, cleft palate, and proliferative retinopathy (PMID:30976112).
This gene has already been associated with relevant phenotypes in OMIM (MIM #619074), but not yet in Gene2Phenotype.Created: 20 Feb 2024, 3:05 p.m. | Last Modified: 20 Feb 2024, 3:05 p.m.
Panel Version: 5.451
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Cleft palate, proliferative retinopathy, and developmental delay, OMIM:619074
Publications
I don't know
Second report of this disorder describes "a patient who presented with cleft palate, prenatal and postnatal severe growth retardation, global developmental delay, dysmorphic facial features and progressive vitreoretinopathy. Whole exome sequencing (WES) revealed a very rare homozygous missense variant in the LRRC32 gene, which resulted in substitution of a highly conserved isoleucine to threonine"Created: 31 Jan 2024, 5:50 p.m. | Last Modified: 31 Jan 2024, 5:50 p.m.
Panel Version: 5.429
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Cleft palate, proliferative retinopathy, and developmental delay
Publications
Red List (low evidence)
Comment on list classification: Rated Red as there is not currently enough evidence that other variants in the LRRC32 gene are disease causing.Created: 31 Jul 2020, 12:45 p.m. | Last Modified: 31 Jul 2020, 12:45 p.m.
Panel Version: 3.212
Not associated with phenotype in OMIM or G2P.
PMID: 30976112 (2019) - homozygous stop-gain variant in LRRC32 (c.1630C>T; p.Arg544Ter) in three affected individuals from two families with global developmental delay, cleft palate, and proliferative retinopathy. In one family developmental quotient (DQ) varied from borderline low in the female (DQ = 72 at 3 years-2 months) to severely delayed in the male (DQ = 57 at 2 years-11 months). The male in the second family was even more severely delayed (DQ = 23 at 3 years-3 months).
Haplotype analysis indicates a founder effect, and therefore further cases are required to substantiate causation (added founder-effect tag).Created: 31 Jul 2020, 12:43 p.m. | Last Modified: 31 Jul 2020, 12:45 p.m.
Panel Version: 3.212
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Global developmental delay; Speech delay; Hypotonia; Cleft palate; Proliferative retinopathy
Publications
I don't know
Three individuals from two consanguineous families segregated the same homozygous bi-allelic variant, c.1630C>T; p.(Arg544Ter), shared haplotype indicative of founder effect. Mouse model has cleft palate and neonatal death.
Sources: LiteratureCreated: 1 May 2020, 10:19 a.m.
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Intellectual disability; cleft palate; proliferative retinopathy
Publications
Gene: lrrc32 has been classified as Amber List (Moderate Evidence).
Publications for gene: LRRC32 were set to 30976112
Phenotypes for gene: LRRC32 were changed from Intellectual disability; cleft palate; proliferative retinopathy to Cleft palate, proliferative retinopathy, and developmental delay, OMIM:619074
Tag founder-effect tag was added to gene: LRRC32.
Gene: lrrc32 has been classified as Red List (Low Evidence).
gene: LRRC32 was added gene: LRRC32 was added to Intellectual disability. Sources: Literature Mode of inheritance for gene: LRRC32 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: LRRC32 were set to 30976112 Phenotypes for gene: LRRC32 were set to Intellectual disability; cleft palate; proliferative retinopathy Review for gene: LRRC32 was set to AMBER
If promoting or demoting a gene, please provide comments to justify a decision to move it.
Genes included in a Genomics England gene panel for a rare disease category (green list) should fit the criteria A-E outlined below.
These guidelines were developed as a combination of the ClinGen DEFINITIVE evidence for a causal role of the gene in the disease(a), and the Developmental Disorder Genotype-Phenotype (DDG2P) CONFIRMED DD Gene evidence level(b) (please see the original references provided below for full details). These help provide a guideline for expert reviewers when assessing whether a gene should be on the green or the red list of a panel.
A. There are plausible disease-causing mutations(i) within, affecting or encompassing an interpretable functional region(ii) of this gene identified in multiple (>3) unrelated cases/families with the phenotype(iii).
OR
B. There are plausible disease-causing mutations(i) within, affecting or encompassing cis-regulatory elements convincingly affecting the expression of a single gene identified in multiple (>3) unrelated cases/families with the phenotype(iii).
OR
C. As definitions A or B but in 2 or 3 unrelated cases/families with the phenotype, with the addition of convincing bioinformatic or functional evidence of causation e.g. known inborn error of metabolism with mutation in orthologous gene which is known to have the relevant deficient enzymatic activity in other species; existence of an animal model which recapitulates the human phenotype.
AND
D. Evidence indicates that disease-causing mutations follow a Mendelian pattern of causation appropriate for reporting in a diagnostic setting(iv).
AND
E. No convincing evidence exists or has emerged that contradicts the role of the gene in the specified phenotype.
(i)Plausible disease-causing mutations: Recurrent de novo mutations convincingly affecting gene function. Rare, fully-penetrant mutations - relevant genotype never, or very rarely, seen in controls. (ii) Interpretable functional region: ORF in protein coding genes miRNA stem or loop. (iii) Phenotype: the rare disease category, as described in the eligibility statement. (iv) Intermediate penetrance genes should not be included.
It’s assumed that loss-of-function variants in this gene can cause the disease/phenotype unless an exception to this rule is known. We would like to collect information regarding exceptions. An example exception is the PCSK9 gene, where loss-of-function variants are not relevant for a hypercholesterolemia phenotype as they are associated with increased LDL-cholesterol uptake via LDLR (PMID: 25911073).
If a curated set of known-pathogenic variants is available for this gene-phenotype, please contact us at [email protected]
We classify loss-of-function variants as those with the following Sequence Ontology (SO) terms:
Term descriptions can be found on the PanelApp homepage and Ensembl.
If you are submitting this evaluation on behalf of a clinical laboratory please indicate whether you report variants in this gene as part of your current diagnostic practice by checking the box
Standardised terms were used to represent the gene-disease mode of inheritance, and were mapped to commonly used terms from the different sources. Below each of the terms is described, along with the equivalent commonly-used terms.
A variant on one allele of this gene can cause the disease, and imprinting has not been implicated.
A variant on the paternally-inherited allele of this gene can cause the disease, if the alternate allele is imprinted (function muted).
A variant on the maternally-inherited allele of this gene can cause the disease, if the alternate allele is imprinted (function muted).
A variant on one allele of this gene can cause the disease. This is the default used for autosomal dominant mode of inheritance where no knowledge of the imprinting status of the gene required to cause the disease is known. Mapped to the following commonly used terms from different sources: autosomal dominant, dominant, AD, DOMINANT.
A variant on both alleles of this gene is required to cause the disease. Mapped to the following commonly used terms from different sources: autosomal recessive, recessive, AR, RECESSIVE.
The disease can be caused by a variant on one or both alleles of this gene. Mapped to the following commonly used terms from different sources: autosomal recessive or autosomal dominant, recessive or dominant, AR/AD, AD/AR, DOMINANT/RECESSIVE, RECESSIVE/DOMINANT.
A variant on one allele of this gene can cause the disease, however a variant on both alleles of this gene can result in a more severe form of the disease/phenotype.
A variant in this gene can cause the disease in males as they have one X-chromosome allele, whereas a variant on both X-chromosome alleles is required to cause the disease in females. Mapped to the following commonly used term from different sources: X-linked recessive.
A variant in this gene can cause the disease in males as they have one X-chromosome allele. A variant on one allele of this gene may also cause the disease in females, though the disease/phenotype may be less severe and may have a later-onset than is seen in males. X-linked inactivation and mosaicism in different tissues complicate whether a female presents with the disease, and can change over their lifetime. This term is the default setting used for X-linked genes, where it is not known definitately whether females require a variant on each allele of this gene in order to be affected. Mapped to the following commonly used terms from different sources: X-linked dominant, x-linked, X-LINKED, X-linked.
The gene is in the mitochondrial genome and variants within this can cause this disease, maternally inherited. Mapped to the following commonly used term from different sources: Mitochondrial.
Mapped to the following commonly used terms from different sources: Unknown, NA, information not provided.
For example, if the mode of inheritance is digenic, please indicate this in the comments and which other gene is involved.