Total submissions: 2
Submitter | RCV | SCV | Clinical significance | Condition | Last evaluated | Review status | Method | Comment |
---|---|---|---|---|---|---|---|---|
Clin |
RCV004596481 | SCV005089679 | likely pathogenic | Deficiency of guanidinoacetate methyltransferase | 2024-04-26 | reviewed by expert panel | curation | The NM_000156.6:c.114C>T (p.Gly38=) variant in GAMT is a synonymous (silent) variant. The computational splicing predictor SpliceAI gives a score of 0.98 for donor gain, predicting that the variant activates a cryptic splice site within exon 1 of GAMT (PP3). This variant has been reported in an individual with GAMT deficiency (PMID: 37305710). This individual was compound heterozygous for this variant and a variant that has been classified as likely pathogenic variant by the ClinGen CCDS VCEP, c.328-1G>A (ClinVar ID 844968), and confirmed in trans by parental testing (PMID: 37305710). This individual had elevated guanidinoacetate levels in plasma and significantly decreased creatine peak on brain MRS (PP4_Strong). This variant is absent from gnomAD v2.1.1 (PM2_Supporting). There is a ClinVar entry for this variant (Variation ID: 1305363). In summary, this variant meets the criteria to be classified as likely pathogenic for GAMT deficiency based on the ACMG/AMP criteria applied, as specified by the ClinGen Cerebral Creatine Deficiency Syndromes Variant Curation Expert Panel (Specifications Version 1.1.0): PM2_Supporting, PM3, PP3, PP4_Strong. (Classification approved by the ClinGen CCDS VCEP on April 26, 2024) |
Gene |
RCV001768570 | SCV001992358 | uncertain significance | not provided | 2019-02-08 | criteria provided, single submitter | clinical testing | Not observed in large population cohorts (Lek et al., 2016) |