NM_003924.4:c.681G>C

Variant names:

• chr4-41746071-C-G
• NM_003924.4:c.681G>C
• PHOX2B p.Ala227Ala

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP7

The NM_003924.4(PHOX2B):​c.681G>C​(p.Ala227Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. A227A) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PHOX2B NM_003924.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -1.39
• 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: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P, ClinGen
• 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: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (REVEL=0.076).
• BP7: Synonymous conserved (PhyloP=-1.39 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_003924.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PHOX2B	NM_003924.4	MANE Select	c.681G>C	p.Ala227Ala	synonymous	Exon 3 of 3	NP_003915.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PHOX2B	ENST00000226382.4	TSL:1 MANE Select	c.681G>C	p.Ala227Ala	synonymous	Exon 3 of 3	ENSP00000226382.2	Q99453
	PHOX2B	ENST00000510424.2	TSL:3	n.502G>C		non_coding_transcript_exon	Exon 3 of 3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.76
CADD	Benign	7.5
DANN	Benign	0.56
PhyloP100		-1.4

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr4-41748088;