rs1553898048

Positions:

• chr4-41747443-T-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_003924.4(PHOX2B):​c.335A>T​(p.Glu112Val) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: PHOX2B NM_003924.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.11

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a DNA_binding_region Homeobox (size 59) in uniprot entity PHX2B_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) in NM_003924.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.847

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PHOX2B	NM_003924.4	c.335A>T	p.Glu112Val	missense_variant	2/3	ENST00000226382.4	NP_003915.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PHOX2B	ENST00000226382.4	c.335A>T	p.Glu112Val	missense_variant	2/3	1	NM_003924.4	ENSP00000226382	P1
PHOX2B	ENST00000510424.2	n.156A>T		non_coding_transcript_exon_variant	2/3	3

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Haddad syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 14, 2017

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 missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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 glutamic acid with valine at codon 112 of the PHOX2B protein (p.Glu112Val). The glutamic acid residue is highly conserved and there is a moderate physicochemical difference between glutamic acid and valine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.38
CADD	Pathogenic	31
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.93	D
Eigen	Uncertain	0.38
Eigen_PC	Uncertain	0.43
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.93	D
M_CAP	Pathogenic	0.35	D
MetaRNN	Pathogenic	0.85	D
MetaSVM	Benign	-0.33	T
MutationAssessor	Benign	1.2	L
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.91	D
PROVEAN	Pathogenic	-6.9	D
REVEL	Pathogenic	0.88
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.058	T
Polyphen		1.0	D
Vest4		0.67
MutPred		0.57		Gain of MoRF binding (P = 0.0354);
MVP		0.99
MPC		2.5
ClinPred		0.99	D
GERP RS		5.4
Varity_R		0.90
gMVP		0.96

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: rs1553898048; hg19: chr4-41749460;