X-8570498-C-G

Variant names:

• chrX-8570498-C-G
• rs387906427
• NM_000216.4:c.1062+1G>C

Variant summary

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

The NM_000216.4(ANOS1):​c.1062+1G>C variant causes a splice donor, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: ANOS1 NM_000216.4 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 6.24
• Publications: 0 publications found

Genes affected

ANOS1 (HGNC:6211): (anosmin 1) Mutations in this gene cause the X-linked Kallmann syndrome. The encoded protein is similar in sequence to proteins known to function in neural cell adhesion and axonal migration. In addition, this cell surface protein is N-glycosylated and may have anti-protease activity. [provided by RefSeq, Jul 2008]

ANOS1 Gene-Disease associations (from GenCC):

• hypogonadotropic hypogonadism 1 with or without anosmia

  Inheritance: XL Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Labcorp Genetics (formerly Invitae)
• Kallmann syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

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

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 4.5, offset of 41, new splice context is: aggGTattt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-8570498-C-G is Pathogenic according to our data. Variant chrX-8570498-C-G is described in ClinVar as Pathogenic. ClinVar VariationId is 2066557.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000216.4. 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
	ANOS1	NM_000216.4	MANE Select	c.1062+1G>C		splice_donor intron	N/A	NP_000207.2
	ANOS1	NM_001440775.1		c.1062+1G>C		splice_donor intron	N/A	NP_001427704.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ANOS1	ENST00000262648.8	TSL:1 MANE Select	c.1062+1G>C		splice_donor intron	N/A	ENSP00000262648.3
	ANOS1	ENST00000488294.1	TSL:2	n.152+1G>C		splice_donor intron	N/A

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 23

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hypogonadotropic hypogonadism 1 with or without anosmia Pathogenic:1

Apr 09, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. Disruption of this splice site has been observed in individuals with Kallmann syndrome (PMID: 16882753, 31200363). This variant is not present in population databases (gnomAD no frequency). This sequence change affects a donor splice site in intron 7 of the ANOS1 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in ANOS1 are known to be pathogenic (PMID: 8504298, 11297579).

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Uncertain	0.070
CADD	Uncertain	24
DANN	Uncertain	0.99
FATHMM_MKL	Pathogenic	0.97	D
PhyloP100		6.2
GERP RS		4.3
Mutation Taster		=5/95	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.87
SpliceAI score (max)		0.94		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.94		Position offset: 1

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

Other links and lift over

dbSNP: rs387906427; hg19: chrX-8538539;