rs201060167
Variant summary
Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1PP3_ModeratePP5_Very_Strong
The NM_002180.3(IGHMBP2):c.1082T>C(p.Leu361Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000117 in 1,613,386 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★).
Frequency
Consequence
NM_002180.3 missense
Scores
Clinical Significance
Conservation
Publications
- autosomal recessive distal spinal muscular atrophy 1Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Ambry Genetics, Genomics England PanelApp, Orphanet, Labcorp Genetics (formerly Invitae)
- Charcot-Marie-Tooth disease axonal type 2SInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)
- hereditary peripheral neuropathyInheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
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ACMG classification
Our verdict: Pathogenic. The variant received 12 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000920 AC: 14AN: 152160Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000558 AC: 14AN: 250754 AF XY: 0.0000590 show subpopulations
GnomAD4 exome AF: 0.000119 AC: 174AN: 1461108Hom.: 0 Cov.: 32 AF XY: 0.000122 AC XY: 89AN XY: 726918 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000919 AC: 14AN: 152278Hom.: 0 Cov.: 32 AF XY: 0.0000672 AC XY: 5AN XY: 74458 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Pathogenic:3
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Published functional studies demonstrate a damaging effect with severe loss of enzymatic activity compared to wild type (Eckart et al., 2012); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 18802676, 26922252, 14681881, 21353777, 17431882, 14506069, 16964485, 23566544, 33210134, 36077311, 27535533, 22157136, 25439726, 22965130, 24388491) -
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Autosomal recessive distal spinal muscular atrophy 1;C4015349:Charcot-Marie-Tooth disease axonal type 2S Pathogenic:2
This sequence change replaces leucine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 361 of the IGHMBP2 protein (p.Leu361Pro). This variant is present in population databases (rs201060167, gnomAD 0.01%). This missense change has been observed in individual(s) with distal spinal muscular atrophy type 1 and/or spinal muscular atrophy with respiratory distress type 1 (PMID: 14506069, 14681881, 18802676). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 245627). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on IGHMBP2 protein function. Experimental studies have shown that this missense change affects IGHMBP2 function (PMID: 22157136). For these reasons, this variant has been classified as Pathogenic. -
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Autosomal recessive distal spinal muscular atrophy 1 Pathogenic:2
ACMG Criteria: PS3, PM2, PM3, PP3, PP5, ; Variant was found in homozygous state. -
Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with Charcot-Marie-Tooth disease, axonal, type 2S (MIM#616155) and neuronopathy, distal hereditary motor, type VI (MIM#604320). (I) 0106 - This gene is associated with autosomal recessive disease. (I) 0200 - Variant is predicted to result in a missense amino acid change from leucine to proline. (I) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD (v2) <0.01 for a recessive condition (15 heterozygotes, 0 homozygotes). (SP) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0600 - Variant is located in the annotated AAA domain (DECIPHER). (I) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. This variant has been reported multiple times as pathogenic, and observed in compound heterozygous individuals with spinal muscular atrophy with respiratory distress (ClinVar, PMID: 23566544, PMID: 22157136). (SP) 1002 - This variant has moderate functional evidence supporting abnormal protein function. Recombinant protein has been proven to result in significantly reduced enzyme activity through an ATPase assay (PMID: 22157136). (SP) 1201 - Heterozygous variant detected in trans with a second pathogenic heterozygous variant (p.(Cys496*)) in a recessive disease. (SP) 1206 - This variant has been shown to be paternally inherited (by trio analysis). (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
Inborn genetic diseases Pathogenic:1
The p.L361P variant (also known as c.1082T>C), located in coding exon 8 of the IGHMBP2 gene, results from a T to C substitution at nucleotide position 1082. The leucine at codon 361 is replaced by proline, an amino acid with similar properties. This alteration has been reported in individuals presenting with early-onset disease, such as SMARD1 (Grohmann K et al. Ann. Neurol., 2003 Dec;54:719-24; Guenther UP et al. Hum. Mutat., 2007 Aug;28:808-15; Guenther UP et al. J. Mol. Med., 2009 Jan;87:31-41; Pitt M et al. Brain, 2003 Dec;126:2682-92). These individuals were reported to have a second IGHMBP2 alteration; however, the phase of the two alterations was only confirmed to be in trans in two individuals (Guenther UP et al. Hum. Mutat., 2007 Aug;28:808-15; Guenther UP et al. J. Mol. Med., 2009 Jan;87:31-41). Functional studies demonstrated that the p.L361P alteration leads to a severe loss of enzymatic activity of the IGHMBP2 protein (Eckart M et al. Pediatrics, 2012 Jan;129:e148-56). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -
Charcot-Marie-Tooth disease axonal type 2S Pathogenic:1
Variant summary: IGHMBP2 c.1082T>C (p.Leu361Pro) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 5.6e-05 in 250754 control chromosomes. c.1082T>C has been reported in the literature in individuals affected with diaphragmatic palsy, Charcot-Marie-Tooth Disease or hereditary motor neuropathy. These data indicate that the variant is likely to be associated with disease. Five clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Charcot-Marie-Tooth disease Uncertain:1
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Distal spinal muscular atrophy Uncertain:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at