rs768420488
Variant summary
Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4_ModerateBS2
The NM_003924.4(PHOX2B):c.785G>T(p.Gly262Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000112 in 1,342,912 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G262D) has been classified as Uncertain significance.
Frequency
Consequence
NM_003924.4 missense
Scores
Clinical Significance
Conservation
Publications
- central hypoventilation syndrome, congenital, 1, with or without Hirschsprung diseaseInheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen, G2P
- Haddad syndromeInheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
- neuroblastoma, susceptibility to, 2Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, G2P
- congenital central hypoventilation syndromeInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Likely_benign. The variant received -6 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| PHOX2B | NM_003924.4 | c.785G>T | p.Gly262Val | missense_variant | Exon 3 of 3 | ENST00000226382.4 | NP_003915.2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000669 AC: 1AN: 149510Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000323 AC: 3AN: 92736 AF XY: 0.0000186 show subpopulations
GnomAD4 exome AF: 0.0000117 AC: 14AN: 1193402Hom.: 0 Cov.: 31 AF XY: 0.00000862 AC XY: 5AN XY: 580288 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000669 AC: 1AN: 149510Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 72864 show subpopulations
ClinVar
Submissions by phenotype
Congenital central hypoventilation Pathogenic:1Uncertain:1
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This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -
Hereditary cancer-predisposing syndrome Uncertain:2
The p.G262V variant (also known as c.785G>T), located in coding exon 3 of the PHOX2B gene, results from a G to T substitution at nucleotide position 785. The glycine at codon 262 is replaced by valine, an amino acid with dissimilar properties. This alteration has been identified in trans with a polyalanine repeat expansion mutation (PARM) with 24 alanines in a 3 year old diagnosed with congenital central hypoventilation syndrome (Sivan Y et al. Am J Med Genet A, 2019 03;179:503-506). This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this alteration remains unclear. -
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Haddad syndrome Uncertain:1
This sequence change replaces glycine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 262 of the PHOX2B protein (p.Gly262Val). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with congenital central hypoventilation syndrome (PMID: 30672101). ClinVar contains an entry for this variant (Variation ID: 467746). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. 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. -
not provided Uncertain:1
In silico analysis supports that this missense variant does not alter protein structure/function; Identified in the heterozygous or homozygous state in individuals with CCHS, both of whom had multiple unaffected relatives also heterozygous for the variant (Sivan et al., 2023); This variant is associated with the following publications: (PMID: 30672101, 37373665, 33958749) -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at