chr4-41747537-C-CTAGA

Position:

• chr4-41747537-C-CTAGA

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 4P and 4B. PVS1_Strong BS2

The NM_003924.4(PHOX2B):​c.242-2_242-1insTCTA variant causes a splice acceptor change. The variant allele was found at a frequency of 0.0000144 in 1,453,482 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.000014 (0 hom.)
• Consequence: PHOX2B NM_003924.4 splice_acceptor
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 4.83

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 Uncertain_significance. Variant got 0 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.19788359 fraction of the gene. Cryptic splice site detected, with MaxEntScore 6.8, offset of 0 (no position change), new splice context is: ctctgtcatactctatctAGttc. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• BS2: High AC in GnomAdExome4 at 21 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PHOX2B	NM_003924.4	c.242-2_242-1insTCTA		splice_acceptor_variant		ENST00000226382.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PHOX2B	ENST00000226382.4	c.242-2_242-1insTCTA		splice_acceptor_variant		1	NM_003924.4	P1
PHOX2B	ENST00000510424.2	n.63-2_63-1insTCTA		splice_acceptor_variant, non_coding_transcript_variant		3

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.0000144 AC: 21 AN: 1453482 Hom.: 0 Cov.: 32 AF XY: 0.0000138 AC XY: 10 AN XY: 723338

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000171

Gnomad4 OTH exome AF: 0.0000332

GnomAD4 genome Cov.: 31

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neuroblastoma, susceptibility to, 2;C5562075:Central hypoventilation syndrome, congenital, 1, with or without Hirschsprung disease Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Jan 03, 2022

- -

Neuroblastoma, susceptibility to, 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Nov 03, 2023

- -

Haddad syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 25, 2023

This sequence change falls in intron 1 of the PHOX2B gene. It does not directly change the encoded amino acid sequence of the PHOX2B protein. This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with PHOX2B-related conditions. ClinVar contains an entry for this variant (Variation ID: 406405). 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. -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs1553898065; hg19: chr4-41749554;