rs121912755

Variant names:

• chr17-44253150-C-T
• rs121912755
• NM_000342.4:c.2279G>A

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000342.4(SLC4A1):​c.2279G>A​(p.Arg760Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,008 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R760W) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: SLC4A1 NM_000342.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7
• Conservation: PhyloP100: 7.83
• Publications: 18 publications found

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]

SLC4A1 Gene-Disease associations (from GenCC):

• autosomal dominant distal renal tubular acidosis

  Inheritance: AD, AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), G2P
• cryohydrocytosis

  Inheritance: AD, Unknown Classification: STRONG, SUPPORTIVE, LIMITED Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), PanelApp Australia
• hereditary spherocytosis type 4

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• southeast Asian ovalocytosis

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet
• renal tubular acidosis, distal, 4, with hemolytic anemia

  Inheritance: AR, AD Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia, Orphanet
• dehydrated hereditary stomatocytosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• hereditary spherocytosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_000342.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-44253151-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 803425.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.99
• PP5: Variant 17-44253150-C-T is Pathogenic according to our data. Variant chr17-44253150-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 17780.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000342.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SLC4A1	NM_000342.4	MANE Select	c.2279G>A	p.Arg760Gln	missense	Exon 17 of 20	NP_000333.1	P02730-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SLC4A1	ENST00000262418.12	TSL:1 MANE Select	c.2279G>A	p.Arg760Gln	missense	Exon 17 of 20	ENSP00000262418.6	P02730-1
	SLC4A1	ENST00000399246.3	TSL:5	c.1181G>A	p.Arg394Gln	missense	Exon 12 of 15	ENSP00000382190.3	A0A0A0MS98

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461008 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 726810

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52546

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112004

Other (OTH) AF: 0.00 AC: 0 AN: 60392

GnomAD4 genome Cov.: 31

Alfa AF: 0.0000333 Hom.: 0

Bravo AF: 0.00000378

ClinVar

ClinVar submissions

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
4	-	-	not provided (4)
2	-	-	Hereditary spherocytosis type 4 (2)
1	-	-	BLOOD GROUP--DIEGO SYSTEM;C1832168:BLOOD GROUP--FROESE;C1832169:BLOOD GROUP--SWANN SYSTEM;C1861453:Cryohydrocytosis;C1862190:BLOOD GROUP--WRIGHT ANTIGEN;C1862191:BLOOD GROUP--WALDNER TYPE;C1862322:Southeast Asian ovalocytosis;C1970028:Malaria, susceptibility to;C2675212:Hereditary spherocytosis type 4;C5436235:Renal tubular acidosis, distal, 4, with hemolytic anemia;CN280572:Autosomal dominant distal renal tubular acidosis (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.69
BayesDel_addAF	Pathogenic	0.46	D
BayesDel_noAF	Pathogenic	0.42
CADD	Pathogenic	32
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.94	D
Eigen	Pathogenic	0.95
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Uncertain	0.17	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.0	H
PhyloP100		7.8
PrimateAI	Uncertain	0.63	T
PROVEAN	Uncertain	-3.4	D
REVEL	Pathogenic	0.90
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.97
MutPred		0.98		Gain of sheet (P = 0.0477)
MVP		0.97
MPC		1.2
ClinPred		1.0	D
GERP RS		4.7
Varity_R		0.97
gMVP		0.97
Mutation Taster		=5/95	disease causing (ClinVar)

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

dbSNP: rs121912755; hg19: chr17-42330518;