1-119712044-A-T

Variant names:

• chr1-119712044-A-T
• rs1650717188
• NM_006623.4:c.22A>T

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PVS1 PM2 PP3 PP5_Moderate

The NM_006623.4(PHGDH):​c.22A>T​(p.Lys8*) variant causes a stop gained change. The variant allele was found at a frequency of 0.0000131 in 152,198 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: 𝑓 0.000013 (0 hom., cov: 33)
• Consequence: PHGDH NM_006623.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 3.72

Genes affected

PHGDH (HGNC:8923): (phosphoglycerate dehydrogenase) This gene encodes the enzyme which is involved in the early steps of L-serine synthesis in animal cells. L-serine is required for D-serine and other amino acid synthesis. The enzyme requires NAD/NADH as a cofactor and forms homotetramers for activity. Mutations in this gene have been found in a family with congenital microcephaly, psychomotor retardation and other symptoms. Multiple alternatively spliced transcript variants have been found, however the full-length nature of most are not known. [provided by RefSeq, Aug 2011]

LOC105378937 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 13 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 58 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 1-119712044-A-T is Pathogenic according to our data. Variant chr1-119712044-A-T is described in ClinVar as [Pathogenic]. Clinvar id is 1393177.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PHGDH	NM_006623.4	c.22A>T	p.Lys8*	stop_gained	Exon 1 of 12	ENST00000641023.2	NP_006614.2
PHGDH	XM_011541226.3	c.22A>T	p.Lys8*	stop_gained	Exon 1 of 14		XP_011539528.1
PHGDH	XR_007058634.1	n.111A>T		non_coding_transcript_exon_variant	Exon 1 of 8
LOC105378937	XR_947757.4	n.-198T>A		upstream_gene_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PHGDH	ENST00000641023.2	c.22A>T	p.Lys8*	stop_gained	Exon 1 of 12		NM_006623.4	ENSP00000493175.1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152198 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152198 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74356

Gnomad4 AFR AF: 0.0000483

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

PHGDH deficiency Pathogenic:1

Sep 15, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Lys8*) in the PHGDH gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in PHGDH are known to be pathogenic (PMID: 14645240, 24836451). This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with PHGDH-related conditions. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.55
CADD	Pathogenic	50
DANN	Uncertain	1.0
Eigen	Pathogenic	0.70
Eigen_PC	Uncertain	0.56
FATHMM_MKL	Uncertain	0.88	D
Vest4		0.68
GERP RS		5.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.69		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.69		Position offset: -2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1650717188; hg19: chr1-120254667;