Total submissions: 2
Submitter | RCV | SCV | Clinical significance | Condition | Last evaluated | Review status | Method | Comment |
---|---|---|---|---|---|---|---|---|
Clin |
RCV002305524 | SCV002600162 | uncertain significance | Deficiency of guanidinoacetate methyltransferase | 2022-06-06 | reviewed by expert panel | curation | The NM_000156.6:c.701C>T variant in GAMT is a missense variant predicted to cause substitution of threonine by isoleucine at amino acid 234 (p.Thr234Ile). The highest population minor allele frequency in gnomAD v2.1.1 is 0.00011 (1/126040) in the African / African American population, which is lower than the ClinGen CCDS VCEP's threshold for PM2_Supporting (<0.0004), meeting this criterion (PM2_Supporting). The computational predictor REVEL gives a score of 0.268 which is below the threshold of 0.5, evidence that does not predict a damaging effect on GAMT function (BP4). To our knowledge, this variant has not been reported in the published literature. It has been previously noted in ClinVar (ID 544252). In summary, this variant meets the criteria to be classified as a variant of uncertain significance for GAMT deficiency. GAMT-specific ACMG/AMP codes met, as specified by the ClinGen Cerebral Creatine Deficiency Syndromes VCEP (Specifications Version 1.1.0): PM2_Supporting, BP4. (Classification approved by the ClinGen CCDS VCEP on June 6, 2022). |
Labcorp Genetics |
RCV000655357 | SCV000777287 | uncertain significance | Cerebral creatine deficiency syndrome | 2022-03-19 | criteria provided, single submitter | clinical testing | This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 234 of the GAMT protein (p.Thr234Ile). This variant is present in population databases (no rsID available, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with GAMT-related conditions. ClinVar contains an entry for this variant (Variation ID: 544252). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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. |