chrX-67545892-T-TG

Variant names:

• chrX-67545892-T-TG
• rs1555969684
• NM_000044.6:c.749dupG

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000044.6(AR):​c.749dupG​(p.Val251CysfsTer54) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 24)
• Consequence: AR NM_000044.6 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 1.84
• Publications: 0 publications found

Genes affected

AR (HGNC:644): (androgen receptor) The androgen receptor gene is more than 90 kb long and codes for a protein that has 3 major functional domains: the N-terminal domain, DNA-binding domain, and androgen-binding domain. The protein functions as a steroid-hormone activated transcription factor. Upon binding the hormone ligand, the receptor dissociates from accessory proteins, translocates into the nucleus, dimerizes, and then stimulates transcription of androgen responsive genes. This gene contains 2 polymorphic trinucleotide repeat segments that encode polyglutamine and polyglycine tracts in the N-terminal transactivation domain of its protein. Expansion of the polyglutamine tract from the normal 9-34 repeats to the pathogenic 38-62 repeats causes spinal bulbar muscular atrophy (SBMA, also known as Kennedy's disease). Mutations in this gene are also associated with complete androgen insensitivity (CAIS). Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Jan 2017]

AR Gene-Disease associations (from GenCC):

• androgen insensitivity syndrome

  Inheritance: XL Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine
• Kennedy disease

  Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, ClinGen, G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• partial androgen insensitivity syndrome

  Inheritance: XL Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp
• complete androgen insensitivity syndrome

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-67545892-T-TG is Pathogenic according to our data. Variant chrX-67545892-T-TG is described in ClinVar as Pathogenic. ClinVar VariationId is 464803.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AR	NM_000044.6	c.749dupG	p.Val251CysfsTer54	frameshift_variant	Exon 1 of 8	ENST00000374690.9	NP_000035.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
AR	ENST00000374690.9	c.749dupG	p.Val251CysfsTer54	frameshift_variant	Exon 1 of 8	1	NM_000044.6	ENSP00000363822.3

Frequencies

GnomAD3 genomes Cov.: 24

GnomAD4 exome Cov.: 56

GnomAD4 genome Cov.: 24

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Androgen resistance syndrome;C1839259:Kennedy disease Pathogenic:1

Dec 13, 2016

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change inserts 1 nucleotide in exon 1 of the AR mRNA (c.749dupG), causing a frameshift at codon 251. This creates a premature translational stop signal (p.Val251Cysfs*54) and is expected to result in an absent or disrupted protein product. While this particular variant has not been reported in the literature, loss-of-function variants in AR are known to be pathogenic (PMID: 19463997). Family studies have indicated that this variant was not present in the parents of an individual with Androgen Insensitivity, which suggests that it was de novo in that affected individual. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.8
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs1555969684; hg19: chrX-66765734;