rs956551152

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PM2PP3

The NM_003924.4(PHOX2B):​c.323C>T​(p.Ala108Val) variant causes a missense change. The variant allele was found at a frequency of 0.000000685 in 1,458,936 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. A108S) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 31)
Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

PHOX2B
NM_003924.4 missense

Scores

8
6
5

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 6.79

Publications

0 publications found
Variant links:
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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

PM1
In a DNA_binding_region Homeobox (size 59) in uniprot entity PHX2B_HUMAN there are 7 pathogenic changes around while only 2 benign (78%) in NM_003924.4
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.772

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PHOX2BNM_003924.4 linkc.323C>T p.Ala108Val missense_variant Exon 2 of 3 ENST00000226382.4 NP_003915.2 Q99453

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PHOX2BENST00000226382.4 linkc.323C>T p.Ala108Val missense_variant Exon 2 of 3 1 NM_003924.4 ENSP00000226382.2 Q99453
PHOX2BENST00000510424.2 linkn.144C>T non_coding_transcript_exon_variant Exon 2 of 3 3

Frequencies

GnomAD3 genomes
Cov.:
31
GnomAD4 exome
AF:
6.85e-7
AC:
1
AN:
1458936
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
725858
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33466
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39692
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86234
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
51174
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
9.00e-7
AC:
1
AN:
1111382
Other (OTH)
AF:
0.00
AC:
0
AN:
60368
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
31

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Haddad syndrome Uncertain:1
Mar 10, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In summary, this variant is a novel missense change with uncertain impact on protein function. 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. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a PHOX2B-related disease. This sequence change replaces alanine with valine at codon 108 of the PHOX2B protein (p.Ala108Val). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and valine. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.76
BayesDel_addAF
Pathogenic
0.29
D
BayesDel_noAF
Pathogenic
0.18
CADD
Pathogenic
29
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.87
D
Eigen
Uncertain
0.49
Eigen_PC
Uncertain
0.58
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.94
D
M_CAP
Benign
0.071
D
MetaRNN
Pathogenic
0.77
D
MetaSVM
Benign
-0.65
T
MutationAssessor
Benign
1.5
L
PhyloP100
6.8
PrimateAI
Pathogenic
0.91
D
PROVEAN
Uncertain
-3.3
D
REVEL
Pathogenic
0.69
Sift
Benign
0.10
T
Sift4G
Uncertain
0.044
D
Polyphen
1.0
D
Vest4
0.66
MutPred
0.35
Loss of ubiquitination at K111 (P = 0.0962);
MVP
0.86
MPC
2.3
ClinPred
0.99
D
GERP RS
5.4
Varity_R
0.57
gMVP
0.92
Mutation Taster
=3/97
disease causing

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

Other links and lift over

dbSNP: rs956551152; hg19: chr4-41749472; API