4-41745944-C-T

Variant names:

• chr4-41745944-C-T
• rs1553897753
• NM_003924.4:c.808G>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_003924.4(PHOX2B):​c.808G>A​(p.Gly270Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G270E) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PHOX2B NM_003924.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 0.416
• Publications: 0 publications found

Genes affected

PHOX2B (HGNC:9143): (paired like homeobox 2B) The DNA-associated protein encoded by this gene is a member of the paired family of homeobox proteins localized to the nucleus. The protein functions as a transcription factor involved in the development of several major noradrenergic neuron populations and the determination of neurotransmitter phenotype. The gene product is linked to enhancement of second messenger-mediated activation of the dopamine beta-hydroylase, c-fos promoters and several enhancers, including cyclic amp-response element and serum-response element. Expansion of a 20 amino acid polyalanine tract in this protein by 5-13 aa has been associated with congenital central hypoventilation syndrome. [provided by RefSeq, Jul 2016]

PHOX2B Gene-Disease associations (from GenCC):

• central hypoventilation syndrome, congenital, 1, with or without Hirschsprung disease

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen, G2P
• Haddad syndrome

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• neuroblastoma, susceptibility to, 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, G2P
• congenital central hypoventilation syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PHOX2B	NM_003924.4	c.808G>A	p.Gly270Arg	missense_variant	Exon 3 of 3	ENST00000226382.4	NP_003915.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PHOX2B	ENST00000226382.4	c.808G>A	p.Gly270Arg	missense_variant	Exon 3 of 3	1	NM_003924.4	ENSP00000226382.2
PHOX2B	ENST00000510424.2	n.*89G>A		downstream_gene_variant		3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Haddad syndrome Uncertain:1

Sep 11, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. This variant has not been reported in the literature in individuals with PHOX2B-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces glycine with arginine at codon 270 of the PHOX2B protein (p.Gly270Arg). The glycine residue is moderately conserved and there is a moderate physicochemical difference between glycine and arginine. -

not provided Uncertain:1

Aug 16, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis indicates that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.48
BayesDel_addAF	Uncertain	0.097	D
BayesDel_noAF	Benign	-0.10
CADD	Uncertain	23
DANN	Uncertain	0.98
DEOGEN2	Benign	0.23	T
Eigen	Benign	0.033
Eigen_PC	Benign	0.037
FATHMM_MKL	Uncertain	0.82	D
LIST_S2	Benign	0.61	T
M_CAP	Pathogenic	0.79	D
MetaRNN	Uncertain	0.61	D
MetaSVM	Uncertain	-0.042	T
MutationAssessor	Benign	0.69	N
PhyloP100		0.42
PrimateAI	Pathogenic	0.95	D
PROVEAN	Benign	-0.45	N
REVEL	Uncertain	0.35
Sift	Benign	0.094	T
Sift4G	Benign	0.069	T
Polyphen		1.0	D
Vest4		0.46
MutPred		0.29		Gain of methylation at G270 (P = 0.0379);
MVP		0.94
MPC		1.3
ClinPred		0.32	T
GERP RS		2.9
Varity_R		0.12
gMVP		0.56
Mutation Taster		=87/13	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs1553897753; hg19: chr4-41747961; COSMIC: COSV105050788; COSMIC: COSV105050788;