rs863225462

Positions:

• chr17-44253228-T-C

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_000342.4(SLC4A1):​c.2201A>G​(p.His734Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: SLC4A1 NM_000342.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter P:1 U:1
• Conservation: PhyloP100: 8.02

Genes affected

SLC4A1 (HGNC:11027): (solute carrier family 4 member 1 (Diego blood group)) The protein encoded by this gene is part of the anion exchanger (AE) family and is expressed in the erythrocyte plasma membrane, where it functions as a chloride/bicarbonate exchanger involved in carbon dioxide transport from tissues to lungs. The protein comprises two domains that are structurally and functionally distinct. The N-terminal 40kDa domain is located in the cytoplasm and acts as an attachment site for the red cell skeleton by binding ankyrin. The glycosylated C-terminal membrane-associated domain contains 12-14 membrane spanning segments and carries out the stilbene disulphonate-sensitive exchange transport of anions. The cytoplasmic tail at the extreme C-terminus of the membrane domain binds carbonic anhydrase II. The encoded protein associates with the red cell membrane protein glycophorin A and this association promotes the correct folding and translocation of the exchanger. This protein is predominantly dimeric but forms tetramers in the presence of ankyrin. Many mutations in this gene are known in man, and these mutations can lead to two types of disease: destabilization of red cell membrane leading to hereditary spherocytosis, and defective kidney acid secretion leading to distal renal tubular acidosis. Other mutations that do not give rise to disease result in novel blood group antigens, which form the Diego blood group system. Southeast Asian ovalocytosis (SAO, Melanesian ovalocytosis) results from the heterozygous presence of a deletion in the encoded protein and is common in areas where Plasmodium falciparum malaria is endemic. One null mutation in this gene is known, resulting in very severe anemia and nephrocalcinosis. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.991

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SLC4A1	NM_000342.4	c.2201A>G	p.His734Arg	missense_variant	17/20	ENST00000262418.12	NP_000333.1
SLC4A1	XM_011525129.3	c.2111A>G	p.His704Arg	missense_variant	16/19		XP_011523431.1
SLC4A1	XM_005257593.6	c.2006A>G	p.His669Arg	missense_variant	15/18		XP_005257650.1
SLC4A1	XM_011525130.2	c.2201A>G	p.His734Arg	missense_variant	17/18		XP_011523432.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SLC4A1	ENST00000262418.12	c.2201A>G	p.His734Arg	missense_variant	17/20	1	NM_000342.4	ENSP00000262418.6
SLC4A1	ENST00000399246.3	c.1103A>G	p.His368Arg	missense_variant	12/15	5		ENSP00000382190.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cryohydrocytosis Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Nov 01, 2005

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 26, 2023

ClinVar contains an entry for this variant (Variation ID: 218183). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Experimental studies have shown that this missense change affects SLC4A1 function (PMID: 17554061, 19907019). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt SLC4A1 protein function. This missense change has been observed in individual(s) with SLC4A1-related disorders (PMID: 16227998). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces histidine, which is basic and polar, with arginine, which is basic and polar, at codon 734 of the SLC4A1 protein (p.His734Arg). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.42
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.94	D;D
Eigen	Pathogenic	0.87
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Pathogenic	1.0	D;D
M_CAP	Uncertain	0.15	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	0.83	D
MutationAssessor	Pathogenic	4.0	H;.
PrimateAI	Uncertain	0.78	T
PROVEAN	Pathogenic	-7.0	D;.
REVEL	Pathogenic	0.90
Sift	Pathogenic	0.0	D;.
Sift4G	Uncertain	0.0020	D;D
Polyphen		1.0	D;.
Vest4		0.98
MutPred		0.98		Gain of MoRF binding (P = 0.0065);.;
MVP		0.97
MPC		1.2
ClinPred		1.0	D
GERP RS		4.6
Varity_R		0.97
gMVP		0.99

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

Publications

LitVar

Other links and lift over

dbSNP: rs863225462; hg19: chr17-42330596;