Total submissions: 5
Submitter | RCV | SCV | Clinical significance | Condition | Last evaluated | Review status | Method | Comment |
---|---|---|---|---|---|---|---|---|
Genetic Services Laboratory, |
RCV001818139 | SCV002064404 | pathogenic | not provided | 2020-01-26 | criteria provided, single submitter | clinical testing | DNA sequence analysis of the RRM2B gene demonstrated a sequence change, c.686G>T, in exon 7 that results in an amino acid change, p.Gly229Val. This sequence change has been previously reported in a homozygous state in two siblings with severe muscular hypotonia, seizures, poor visual contact, feeding difficulties, failure to thrive, lactic acidosis and proximal renal tubulopathy in one sibling (PMID: 19138848). Each unaffected parent was heterozygous for the change. Southern blot analysis of patient's muscle tissue showed severe mtDNA depletion, about 1 to 4% of normal controls. This sequence change has been described in the gnomAD database with a low overall population frequency of 0.0016% (dbSNP rs121918311); however it has not been observed in the homozygous state in any individuals. The p.Gly229Val change affects a highly conserved amino acid residue located in a diferric iron center of the ribonucleotide reductase or RRM2B protein that is known to be functional. The p.Gly229Val substitution appears to be deleterious using several in-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL). These collective evidences indicate that this sequence change is pathogenic. |
Labcorp Genetics |
RCV001818139 | SCV002211890 | uncertain significance | not provided | 2023-05-15 | criteria provided, single submitter | clinical testing | An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 5392). This missense change has been observed in individuals with clinical features of RRM2B-related conditions (PMID: 19138848, 21646632, 27290639, 33300680). It has also been observed to segregate with disease in related individuals. This variant is present in population databases (rs121918311, gnomAD 0.003%). This sequence change replaces glycine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 229 of the RRM2B protein (p.Gly229Val). 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. |
Mayo Clinic Laboratories, |
RCV001818139 | SCV005413864 | likely pathogenic | not provided | 2024-05-31 | criteria provided, single submitter | clinical testing | PP1_moderate, PP3, PM3_strong, PS4_moderate |
OMIM | RCV000005723 | SCV000025905 | pathogenic | Mitochondrial DNA depletion syndrome 8a | 2009-02-01 | no assertion criteria provided | literature only | |
Gene |
RCV000119005 | SCV000153703 | not provided | RRM2B-related mitochondrial disease | no assertion provided | literature only |