rs150719105
Variant summary
Our verdict is Pathogenic. The variant received 17 ACMG points: 18P and 1B. PS1PM1PM5PP2PP3PP5_Very_StrongBP4
The NM_000303.3(PMM2):c.430T>C(p.Phe144Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000338 in 1,566,774 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. F144V) has been classified as Likely pathogenic.
Frequency
Consequence
NM_000303.3 missense
Scores
Clinical Significance
Conservation
Publications
- congenital disorder of glycosylation type IInheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health
- PMM2-congenital disorder of glycosylationInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Orphanet, PanelApp Australia, ClinGen
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ACMG classification
Our verdict: Pathogenic. The variant received 17 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| PMM2 | ENST00000268261.9 | c.430T>C | p.Phe144Leu | missense_variant | Exon 5 of 8 | 1 | NM_000303.3 | ENSP00000268261.4 |
Frequencies
GnomAD3 genomes AF: 0.0000789 AC: 12AN: 152154Hom.: 0 Cov.: 34 show subpopulations
GnomAD2 exomes AF: 0.000165 AC: 31AN: 188306 AF XY: 0.000119 show subpopulations
GnomAD4 exome AF: 0.0000290 AC: 41AN: 1414502Hom.: 0 Cov.: 30 AF XY: 0.0000228 AC XY: 16AN XY: 700236 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000788 AC: 12AN: 152272Hom.: 0 Cov.: 34 AF XY: 0.0000806 AC XY: 6AN XY: 74454 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
PMM2-congenital disorder of glycosylation Pathogenic:9
For recessive disorders, detected in trans with a pathogenic variant.;Multiple lines of computational evidence support a deleterious effect on the gene or gene product (conservation, evolutionary, splicing impact, etc).;Co-segregation with disease in multiple affected family members in a gene definitively known to cause the disease.
The PMM2 c.430T>C; p.Phe144Leu variant (rs150719105, ClinVar Variation ID: 197658) is reported in the literature in individuals affected with congenital disorder of glycosylation, including individuals who also carry a pathogenic variant in trans (Kane 2016, Kondo 1999, Lin 2020). This variant is found in the general population with an overall allele frequency of 0.02% (37/219716 alleles) in the Genome Aggregation Database (v2.1.1). Computational analyses predict that this variant is deleterious REVEL: 0.956). Based on available information, this variant is considered to be likely pathogenic. References: Kane MS et al. Mitotic Intragenic Recombination: A Mechanism of Survival for Several Congenital Disorders of Glycosylation. Am J Hum Genet. 2016 Feb 4;98(2):339-46. PMID: 26805780. Kondo I et al. Missense mutations in phosphomannomutase 2 gene in two Japanese families with carbohydrate-deficient glycoprotein syndrome type 1. Clin Genet. 1999 Jan;55(1):50-4. PMID: 10066032. Lin L et al. Clinical and genetic characteristics and prenatal diagnosis of patients presented GDD/ID with rare monogenic causes. Orphanet J Rare Dis. 2020 Nov 11;15(1):317. PMID: 33176815.
This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com.
This variant is a missense mutation. REVEL prediction results suggest that this variant has a damaging effect on the gene or gene product.
This sequence change replaces phenylalanine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 144 of the PMM2 protein (p.Phe144Leu). This variant is present in population databases (rs150719105, gnomAD 0.2%). This missense change has been observed in individual(s) with PMM2-related disease (PMID: 10066032, 28122681, 30687093). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 197658). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt PMM2 protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic.
Variant summary: PMM2 c.430T>C (p.Phe144Leu) results in a non-conservative amino acid change in the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function all suggest that this variant is likely to be disruptive. The variant allele was found at a frequency of 0.00016 in 188306 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in PMM2 causing Congenital Disorder Of Glycosylation Type 1a (0.00016 vs 0.0056), allowing no conclusion about variant significance. c.430T>C has been observed in multiple individuals affected with Congenital Disorder Of Glycosylation Type 1a (Kondo_1999, Al Teneiji_2017, Lin_2020, Wang_2019). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 28122681, 32635232, 10066032, 33176815, 10392743, 30687093). ClinVar contains an entry for this variant (Variation ID: 197658). Based on the evidence outlined above, the variant was classified as pathogenic.
not provided Pathogenic:2
The F144L variant has previously been reported in unrelated individuals with congenital disorder of glycosylation type 1a (CDG-1a) who were heterozygous for F144L and another missense variant in the PMM2 gene, although the phase of these variants was not reported (Kondo et al., 1999; Kane et al., 2016). The 1000 Genomes Project Consortium reports F144L was observed in 2/1008 alleles from individuals of East Asian background. The F144L variant is a conservative amino acid substitution, which is not likely to impact secondary protein structure as these residues share similar properties. This substitution occurs at a position that is conserved across species, and in silico analysis predicts this variant is probably damaging to the protein structure/function. Missense variants in nearby residues (E139K, R141H, D148N) have been reported in the Human Gene Mutation Database in association with CDG-1a (Stenson et al., 2014), supporting the functional importance of this region of the protein. Therefore, this variant is likely pathogenic; however, the possibility that it is benign cannot be excluded.
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at