Submissions for variant NM_006623.4(PHGDH):c.1258G>A (p.Glu420Lys)

gnomAD frequency: 0.00019  dbSNP: rs140979375

Total submissions: 5

Submitter	RCV	SCV	Clinical significance	Condition	Last evaluated	Review status	Method	Comment
Women's Health and Genetics/Laboratory Corporation of America, LabCorp	RCV000781718	SCV000919985	uncertain significance	not specified	2023-01-05	criteria provided, single submitter	clinical testing	Variant summary: PHGDH c.1258G>A (p.Glu420Lys) results in a conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00012 in 249932 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in PHGDH causing Phosphoglycerate Dehydrogenase Deficiency (0.00012 vs 0.0026), allowing no conclusion about variant significance. To our knowledge, no occurrence of c.1258G>A in individuals affected with Phosphoglycerate Dehydrogenase Deficiency and no experimental evidence demonstrating its impact on protein function have been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance.
Illumina Laboratory Services, Illumina	RCV001097501	SCV001253788	uncertain significance	PHGDH deficiency	2018-01-12	criteria provided, single submitter	clinical testing	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease.
Invitae	RCV001097501	SCV001568160	uncertain significance	PHGDH deficiency	2022-07-30	criteria provided, single submitter	clinical testing	This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 420 of the PHGDH protein (p.Glu420Lys). This variant is present in population databases (rs140979375, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with PHGDH-related conditions. ClinVar contains an entry for this variant (Variation ID: 633351). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The lysine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect 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.
Genome-Nilou Lab	RCV003338789	SCV004049126	uncertain significance	Neu-Laxova syndrome 1	2023-04-11	criteria provided, single submitter	clinical testing
Genome-Nilou Lab	RCV001097501	SCV004049127	uncertain significance	PHGDH deficiency	2023-04-11	criteria provided, single submitter	clinical testing