rs375724532
Variant summary
Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM1BP4_Moderate
The NM_199242.3(UNC13D):c.2243C>T(p.Ala748Val) variant causes a missense change. The variant allele was found at a frequency of 0.0000879 in 1,591,872 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A748T) has been classified as Uncertain significance.
Frequency
Consequence
NM_199242.3 missense
Scores
Clinical Significance
Conservation
Publications
- familial hemophagocytic lymphohistiocytosis 3Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Laboratory for Molecular Medicine, Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen
- hereditary hemophagocytic lymphohistiocytosisInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Uncertain_significance. The variant received 0 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000854 AC: 13AN: 152222Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000913 AC: 20AN: 218964 AF XY: 0.0000748 show subpopulations
GnomAD4 exome AF: 0.0000882 AC: 127AN: 1439532Hom.: 1 Cov.: 33 AF XY: 0.0000922 AC XY: 66AN XY: 716080 show subpopulations
GnomAD4 genome AF: 0.0000853 AC: 13AN: 152340Hom.: 0 Cov.: 33 AF XY: 0.0000537 AC XY: 4AN XY: 74488 show subpopulations
ClinVar
Submissions by phenotype
not specified Uncertain:2
Variant summary: UNC13D c.2243C>T (p.Ala748Val) results in a non-conservative amino acid change located in the MUN domain (IPR010439) of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 8.8e-05 in 1585934 control chromosomes in the gnomAD database (v4.1 dataset), including 1 homozygote. This frequency is not higher than the estimated maximum expected for a pathogenic variant in UNC13D causing Familial Hemophagocytic Lymphohistiocytosis (0.0027), allowing no conclusion about variant significance. The variant, c.2243C>T, has been reported in the literature in heterozygous state individuals affected with (suspected) Familial Hemophagocytic Lymphohistiocytosis (e.g. Zhang_2014, McCreary_2019, Xinh_2021), however in at least one of these cases variants found in a different gene could possibly explain the phenotype (McCreary_2019). These reports do not provide unequivocal conclusions about association of the variant with Familial Hemophagocytic Lymphohistiocytosis. At least one publication reported experimental evidence evaluating an impact on protein function, and demonstrated normal activity for the variant protein (Noori_2023). The following publications have been ascertained in the context of this evaluation (PMID: 31664448, 24916509, 31664448, 34339548). ClinVar contains an entry for this variant (Variation ID: 533089). Based on the evidence outlined above, the variant was classified as VUS-possibly benign. -
DNA sequence analysis of the UNC13D gene demonstrated a sequence change, c.2243C>T, in exon 23 that results in an amino acid change, p.Ala748Val. This sequence change has been described in gnomAD with a low frequency of 0.053% (dbSNP rs375724532) in the East Asian sub-population. The p.Ala748Val change affects a moderately conserved amino acid residue located in a domain of the UNC13D protein that is not known to be functional. The p.Gln377Arg substitution appears to be benign using several in-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD,REVEL). This sequence change has been reported in the heterozygous state in an individual with a clinical suspicion of hemophagocytic lymphohistiocytosis. This individual was also reported to have a heterozygous change in the PRF1 gene, suggesting a digenic mode of inheritance (PMID:24916509). Due to the lack of sufficient evidences, the clinical significance of the p.Gln377Arg change remains unknown at this time. -
Familial hemophagocytic lymphohistiocytosis 3 Uncertain:2
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This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 748 of the UNC13D protein (p.Ala748Val). This variant is present in population databases (rs375724532, gnomAD 0.06%). This missense change has been observed in individual(s) with hemophagocytic lymphohistiocytosis (PMID: 24916509). ClinVar contains an entry for this variant (Variation ID: 533089). 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) performed at Invitae indicates that this missense variant is not expected to disrupt UNC13D protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
not provided Uncertain:1
Identified as heterozygous without a second variant in an individual in the literature (Zhang et al., 2014) with familial hemophagocytic lymphohistiocytosis who also had a single heterozygous variant in the PRF1 gene suggesting possible digenic inheritance; In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 24916509) -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at