8-41708992-C-T

Position:

• chr8-41708992-C-T

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM2 PP5_Very_Strong

The NM_000037.4(ANK1):​c.1801-17G>A variant causes a splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,066 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: ANK1 NM_000037.4 splice_polypyrimidine_tract, intron
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: -1.04

Genes affected

ANK1 (HGNC:492): (ankyrin 1) Ankyrins are a family of proteins that link the integral membrane proteins to the underlying spectrin-actin cytoskeleton and play key roles in activities such as cell motility, activation, proliferation, contact and the maintenance of specialized membrane domains. Multiple isoforms of ankyrin with different affinities for various target proteins are expressed in a tissue-specific, developmentally regulated manner. Most ankyrins are typically composed of three structural domains: an amino-terminal domain containing multiple ankyrin repeats; a central region with a highly conserved spectrin binding domain; and a carboxy-terminal regulatory domain which is the least conserved and subject to variation. Ankyrin 1, the prototype of this family, was first discovered in the erythrocytes, but since has also been found in brain and muscles. Mutations in erythrocytic ankyrin 1 have been associated in approximately half of all patients with hereditary spherocytosis. Complex patterns of alternative splicing in the regulatory domain, giving rise to different isoforms of ankyrin 1 have been described. Truncated muscle-specific isoforms of ankyrin 1 resulting from usage of an alternate promoter have also been identified. [provided by RefSeq, Dec 2008]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 8-41708992-C-T is Pathogenic according to our data. Variant chr8-41708992-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 513.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
ANK1	NM_000037.4	c.1801-17G>A		splice_polypyrimidine_tract_variant, intron_variant		ENST00000289734.13	NP_000028.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ANK1	ENST00000289734.13	c.1801-17G>A		splice_polypyrimidine_tract_variant, intron_variant		1	NM_000037.4	ENSP00000289734	A2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461066 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 726852

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary spherocytosis type 1 Pathogenic:3

Likely pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Dec 19, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Department of Genetic, Henri Mondor Hospital, Assistance Publique des Hôpitaux de Paris	Feb 27, 2018	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Sep 29, 2023	The ANK1 c.1801-17G>A variant (rs786205243) has been reported in multiple individuals from families affected with hereditary spherocytosis (HS) (Duru 1992, Edelman 2007, Kang 2020). This variant is also reported in ClinVar (Variation ID: 513). This variant is absent from the Genome Aggregation Database, indicating it is not a common polymorphism. This is an intronic variant in a moderately conserved nucleotide, and computational analyses (Alamut Visual Plus v.1.5.1) predict that this variant does not alter splicing in a significant way. However, in-vitro functional assays suggest altered splicing by creating a novel cryptic acceptor splice site. Based on available information, this variant is considered to be likely pathogenic. REFERENCES Duru F et al. Homozygosity for dominant form of hereditary spherocytosis. Br J Haematol. 1992 Nov. PMID: 1486040 Edelman EJ et al. A complex splicing defect associated with homozygous ankyrin-deficient hereditary spherocytosis. Blood. 2007 Jun 15. PMID: 17327413 Kang LL et al. Gilbert's syndrome coexisting with hereditary spherocytosis might not be rare: Six case reports. World J Clin Cases. 2020 May 26. PMID: 32518793 -

not provided Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	Sep 07, 2021	PS3, PM2 -
Likely pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Sep 01, 2019	- -

Spherocytosis, type 1, autosomal recessive Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Jun 15, 2007

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.75
CADD	Benign	18
DANN	Benign	0.69
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.40		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.40		Position offset: -2

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

Publications

LitVar

Other links and lift over

dbSNP: rs786205243; hg19: chr8-41566510;