4-41745984-TGCCGCTGCCGCCGCCGCCGCTGCCGCGGCCGCC-TGCCGCTGCCGCCGCCGCCGCTGCCGCGGCCGCCGCCGCTGCCGCCGCCGCCGCTGCCGCGGCCGCC

Variant names:

• chr4-41745984-T-TGCCGCTGCCGCCGCCGCCGCTGCCGCGGCCGCC
• rs757850760
• NM_003924.4:c.735_767dupGGCGGCCGCGGCAGCGGCGGCGGCGGCAGCGGC

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PP5_Moderate BP3

The NM_003924.4(PHOX2B):​c.735_767dupGGCGGCCGCGGCAGCGGCGGCGGCGGCAGCGGC​(p.Ala246_Ala256dup) variant causes a disruptive inframe insertion change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. It is difficult to determine the true allele frequency of this variant because it is of type INS_BIG, and the frequency of such variant types in population databases may be underestimated and unreliable. Variant has been reported in ClinVar as Pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. A256A) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PHOX2B NM_003924.4 disruptive_inframe_insertion
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 3.23
• 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 1 ACMG points.

• PP5: Variant 4-41745984-T-TGCCGCTGCCGCCGCCGCCGCTGCCGCGGCCGCC is Pathogenic according to our data. Variant chr4-41745984-T-TGCCGCTGCCGCCGCCGCCGCTGCCGCGGCCGCC is described in ClinVar as Pathogenic. ClinVar VariationId is 1758455.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP3: Nonframeshift variant in repetitive region in NM_003924.4

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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PHOX2B	NM_003924.4	MANE Select	c.735_767dupGGCGGCCGCGGCAGCGGCGGCGGCGGCAGCGGC	p.Ala246_Ala256dup	disruptive_inframe_insertion	Exon 3 of 3	NP_003915.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PHOX2B	ENST00000226382.4	TSL:1 MANE Select	c.735_767dupGGCGGCCGCGGCAGCGGCGGCGGCGGCAGCGGC	p.Ala246_Ala256dup	disruptive_inframe_insertion	Exon 3 of 3	ENSP00000226382.2
	PHOX2B	ENST00000510424.2	TSL:3	n.*16_*48dupGGCGGCCGCGGCAGCGGCGGCGGCGGCAGCGGC		downstream_gene	N/A

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:1

Aug 29, 2024

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Ala241[31] pathogenic mutation, located in coding exon 3 of the PHOX2B gene, results from an expansion of the polyalanine repeat region from 20 to 31 repeats. This expansion mutation is associated with congenital central hypoventilation syndrome (Rossor T et al. Eur. J. Pediatr., 2014 Dec;173(12):1727-30). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		3.2
Mutation Taster		=73/27	polymorphism

Splicing

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

Other links and lift over

dbSNP: rs757850760; hg19: chr4-41748001;