4-41748376-C-T

Position:

• chr4-41748376-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_003924.4(PHOX2B):​c.235G>A​(p.Ala79Thr) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar 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:3
• Conservation: PhyloP100: 4.88

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-AS1 (HGNC:40457): (PHOX2B antisense RNA 1)

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.18428835).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PHOX2B	NM_003924.4	c.235G>A	p.Ala79Thr	missense_variant	1/3	ENST00000226382.4	NP_003915.2
PHOX2B-AS1	NR_187403.1	n.28C>T		non_coding_transcript_exon_variant	1/4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PHOX2B	ENST00000226382.4	c.235G>A	p.Ala79Thr	missense_variant	1/3	1	NM_003924.4	ENSP00000226382.2
PHOX2B-AS1	ENST00000508038.1	n.84C>T		non_coding_transcript_exon_variant	1/5	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neuroblastoma, susceptibility to, 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Mar 16, 2018

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. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 01, 2024

The p.A79T variant (also known as c.235G>A), located in coding exon 1 of the PHOX2B gene, results from a G to A substitution at nucleotide position 235. The alanine at codon 79 is replaced by threonine, an amino acid with similar properties. This amino acid position is highly 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 variant remains unclear. -

Congenital central hypoventilation Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Mar 16, 2018

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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.097
BayesDel_addAF	Uncertain	0.040	T
BayesDel_noAF	Benign	-0.18
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Benign	0.19	T
Eigen	Benign	-0.15
Eigen_PC	Benign	0.11
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.86	D
M_CAP	Benign	0.053	D
MetaRNN	Benign	0.18	T
MetaSVM	Benign	-0.35	T
MutationAssessor	Benign	-1.1	N
PrimateAI	Pathogenic	0.85	D
PROVEAN	Benign	-0.12	N
REVEL	Uncertain	0.40
Sift	Benign	0.21	T
Sift4G	Benign	0.68	T
Polyphen		0.16	B
Vest4		0.24
MutPred		0.27		Gain of glycosylation at A79 (P = 0.0162);
MVP		0.59
MPC		1.6
ClinPred		0.47	T
GERP RS		5.6
Varity_R		0.22
gMVP		0.86

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

Publications

LitVar

Other links and lift over

dbSNP: rs1733979302; hg19: chr4-41750393;