rs763283033
Variant summary
Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2PP3PP5
The NM_152393.4(KLHL40):c.931C>A(p.Arg311Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000867 in 1,614,032 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 Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_152393.4 missense
Scores
Clinical Significance
Conservation
Publications
- nemaline myopathy 8Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics, G2P
- severe congenital nemaline myopathyInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Uncertain_significance. The variant received 4 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152182Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000239 AC: 6AN: 251382 AF XY: 0.0000294 show subpopulations
GnomAD4 exome AF: 0.00000821 AC: 12AN: 1461850Hom.: 0 Cov.: 30 AF XY: 0.00000963 AC XY: 7AN XY: 727230 show subpopulations
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152182Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 74352 show subpopulations
ClinVar
Submissions by phenotype
Nemaline myopathy 8 Pathogenic:4Uncertain:1
This sequence change replaces arginine, which is basic and polar, with serine, which is neutral and polar, at codon 311 of the KLHL40 protein (p.Arg311Ser). This variant is present in population databases (rs763283033, gnomAD 0.02%). This missense change has been observed in individual(s) with clinical features of nemaline myopathy (PMID: 26578207; Invitae). ClinVar contains an entry for this variant (Variation ID: 474339). Advanced 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 at Invitae 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 KLHL40 protein function. This variant disrupts the p.Arg311 amino acid residue in KLHL40. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 23746549). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
The missense c.931C>A (p.Arg311Ser) variant in KLHL40 gene has been reported previously in homozygous state in individuals affected nemaline myopathy (Ravenscroft et al. 2014; Todd et al. 2015). Another missense [c.932G>T p.Arg311Leu] variant at this residue has previously been reported in trans with a pathogenic missense [c.1516A>C p.Thr506Pro] variant (Ravenscroft et al. 2013; Todd et al. 2015). The p.Arg311Ser variant is reported with an allele frequency of 0.002% in the gnomAD exomes database and is novel (not in any individuals) in 1000 Genomes database. This variant has been reported to the ClinVar database as Uncertain Significance / Likely Pathogenic. The amino acid change p.Arg311Ser in KLHL40 is predicted as conserved by GERP++ and PhyloP across 100 vertebrates. The amino acid Arg at position 311 is changed to a Ser changing protein sequence and it might alter its composition and physico-chemical properties. For these reasons, this variant has been classified as Likely Pathogenic. -
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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 nemaline myopathy 8 (MIM#615348). (I) 0106 - This gene is associated with autosomal recessive disease. (I) 0200 - Variant is predicted to result in a missense amino acid change from arginine to serine. (I) 0252 - This variant is homozygous. (I) 0304 - Variant is present in gnomAD <0.01 for a recessive condition (v2: 6 heterozygotes, 0 homozygotes). (SP) 0309 - Multiple alternative amino acid changes at the same position have been observed in gnomAD (Highest allele count in v2: 1 heterozygote, 0 homozygotes). (I) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0604 - Variant is not located in an established domain, motif, hotspot or informative constraint region. (I) 0703 - Another missense variant comparable to the one identified in this case has moderate previous evidence for pathogenicity. p.(Arg311Leu) has been reported in one compound heterozygote and one homozygote with nemaline myopathy (PMID: 23746549, 30665247). (SP) 0803 - This variant has limited previous evidence of pathogenicity in unrelated individuals. One homozygote was reported from a cohort diagnosed with fetal akinesia deformation sequence, arthrogryposis, or a severe congenital myopathy (PMID: 26578207). Two homozygotes with features including myopathy, neonatal hypotonia and respiratory distress were reported in DECIPHER. In addition, this variant has been classified as VUS in ClinVar. (SP) 1007 - No published functional evidence has been identified for this variant. (I) 1209 - This variant has been shown to be both maternally and paternally inherited (biallelic) (by trio analysis). (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
not provided Uncertain:1
In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 26578207, 23746549) -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at