rs969552874

Positions:

• chr14-102929923-G-C

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The ENST00000299155.10(AMN):​c.844-1G>C variant causes a splice acceptor change. The variant allele was found at a frequency of 0.0000131 in 152,222 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 Likely pathogenic (★★).

• Frequency: Genomes: 𝑓 0.000013 (0 hom., cov: 33)
• Consequence: AMN ENST00000299155.10 splice_acceptor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 4.53

Genes affected

AMN (HGNC:14604): (amnion associated transmembrane protein) The protein encoded by this gene is a type I transmembrane protein. It is thought to modulate bone morphogenetic protein (BMP) receptor function by serving as an accessory or coreceptor, and thus facilitates or hinders BMP binding. It is known that the mouse AMN gene is expressed in the extraembryonic visceral endoderm layer during gastrulation, but it is found to be mutated in amnionless mouse. The encoded protein has sequence similarity to short gastrulation (Sog) and procollagen IIA proteins in Drosophila. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.11894273 fraction of the gene. Cryptic splice site detected, with MaxEntScore 7.6, offset of 6, new splice context is: gtccccctccccaccctcAGtac. Cryptic site results in inframe 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 14-102929923-G-C is Pathogenic according to our data. Variant chr14-102929923-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 567966.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
AMN	NM_030943.4	c.844-1G>C		splice_acceptor_variant		ENST00000299155.10	NP_112205.2
AMN	XM_011537202.4	c.682-1G>C		splice_acceptor_variant			XP_011535504.1
AMN	XM_011537203.4	c.682-1G>C		splice_acceptor_variant			XP_011535505.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
AMN	ENST00000299155.10	c.844-1G>C		splice_acceptor_variant		1	NM_030943.4	ENSP00000299155	P1
AMN	ENST00000559789.1	c.127-242G>C		intron_variant		3		ENSP00000452831
AMN	ENST00000541086.5	n.1590-1G>C		splice_acceptor_variant, non_coding_transcript_variant		2
AMN	ENST00000558590.1	n.807-1G>C		splice_acceptor_variant, non_coding_transcript_variant		2

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152222 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000482

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 33

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152222 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74374

Gnomad4 AFR AF: 0.0000482

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000113

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Imerslund-Grasbeck syndrome type 2 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Jul 09, 2021

- -

Imerslund-Grasbeck syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 04, 2023

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 567966). This variant has not been reported in the literature in individuals affected with AMN-related conditions. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change affects an acceptor splice site in intron 8 of the AMN 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 AMN are known to be pathogenic (PMID: 12590260, 22929189). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Benign	-0.17
CADD	Pathogenic	35
DANN	Uncertain	0.98
Eigen	Pathogenic	0.73
Eigen_PC	Uncertain	0.48
FATHMM_MKL	Benign	0.75	D
MutationTaster	Benign	1.0	D
GERP RS		3.2

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.91
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.95		Position offset: 7
DS_AL_spliceai		0.99		Position offset: 1

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

Publications

LitVar

Other links and lift over

dbSNP: rs969552874; hg19: chr14-103396260;