chr20-36935110-C-T
Variant summary
Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM1PM5PP3_StrongPP5_Very_Strong
The NM_015474.4(SAMHD1):c.428G>A(p.Arg143His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000118 in 1,613,778 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 14/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R143L) has been classified as Uncertain significance.
Frequency
Consequence
NM_015474.4 missense
Scores
Clinical Significance
Conservation
Publications
- Aicardi-Goutieres syndrome 5Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, PanelApp Australia, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, G2P
- Moyamoya diseaseInheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp
- Aicardi-Goutieres syndromeInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- familial chilblain lupusInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- chilblain lupus 2Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
- chilblain lupusInheritance: AD Classification: NO_KNOWN Submitted by: Illumina
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ACMG classification
Our verdict: Pathogenic. The variant received 16 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt | 
|---|---|---|---|---|---|---|---|---|
| SAMHD1 | NM_015474.4 | c.428G>A | p.Arg143His | missense_variant | Exon 4 of 16 | ENST00000646673.2 | NP_056289.2 | |
| SAMHD1 | NM_001363729.2 | c.428G>A | p.Arg143His | missense_variant | Exon 4 of 15 | NP_001350658.1 | ||
| SAMHD1 | NM_001363733.2 | c.428G>A | p.Arg143His | missense_variant | Exon 4 of 16 | NP_001350662.1 | 
Ensembl
Frequencies
GnomAD3 genomes  0.00000657  AC: 1AN: 152098Hom.:  0  Cov.: 31 show subpopulations 
GnomAD2 exomes  AF:  0.0000119  AC: 3AN: 251476 AF XY:  0.00000736   show subpopulations 
GnomAD4 exome  AF:  0.0000123  AC: 18AN: 1461680Hom.:  0  Cov.: 30 AF XY:  0.0000138  AC XY: 10AN XY: 727144 show subpopulations 
Age Distribution
GnomAD4 genome  0.00000657  AC: 1AN: 152098Hom.:  0  Cov.: 31 AF XY:  0.00  AC XY: 0AN XY: 74288 show subpopulations 
ClinVar
Submissions by phenotype
Aicardi-Goutieres syndrome 5    Pathogenic:2Other:1 
This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 143 of the SAMHD1 protein (p.Arg143His). This variant is present in population databases (rs369035155, gnomAD 0.004%). This missense change has been observed in individuals with Aicardi-Goutières syndrome (PMID: 19525956, 33683010; Invitae). ClinVar contains an entry for this variant (Variation ID: 126411). 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 expected to disrupt SAMHD1 protein function with a positive predictive value of 80%. Experimental studies have shown that this missense change affects SAMHD1 function (PMID: 28229507, 29379009). This variant disrupts the p.Arg143 amino acid residue in SAMHD1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 19525956, 26431200, 28229507). 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. -
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[ACMG/AMP: PS3, PM2, PM5, PP3, PP5] This alteration is supported by well-established in vitro or in vivo functional studies to have a damaging effect on protein function or splicing [PS3], is absent from or rarely observed in large-scale population databases [PM2], is a novel missense change at an amino residue where a different missense change has been deemed to be pathogenic [PM5], is predicted to be damaging by multiple functional prediction tools [PP3], was reported as a pathogenic/likely pathogenic alteration by a reputable source (ClinVar or other correspondence from a clinical testing laboratory) [PP5]. -
not provided    Pathogenic:2 
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Published functional studies demonstrate that this variant has a damaging effect and leads to a loss of protein function (PMID: 28229507); This variant is associated with the following publications: (PMID: 19525956, 30487145, 23364794, 22056990, 22149989, 34055681, 33683010, 27943079, 29379009, 28229507, 32371413) -
Computational scores
Source: 
Splicing
 Find out detailed SpliceAI scores and Pangolin per-transcript scores at