X-67545197-G-GA

Variant names:

• chrX-67545197-G-GA
• NM_000044.6:c.52dupA

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_000044.6(AR):​c.52dupA​(p.Thr18AsnfsTer66) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 21)
• Consequence: AR NM_000044.6 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 1.20
• 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 10 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 324 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AR	NM_000044.6	c.52dupA	p.Thr18AsnfsTer66	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.52dupA	p.Thr18AsnfsTer66	frameshift_variant	Exon 1 of 8	1	NM_000044.6	ENSP00000363822.3

Frequencies

GnomAD3 genomes Cov.: 21

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 21

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Androgen resistance syndrome;C1839259:Kennedy disease Pathogenic:1

Aug 17, 2020

Invitae

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Thr18Lysfs*66) in the AR gene. It is expected to result in an absent or disrupted protein product. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with AR-related conditions. Loss-of-function variants in AR are known to be pathogenic (PMID: 19463997). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.2

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

Other links and lift over

hg19: chrX-66765039;