Identification of seven novel mutations including the first two genomic rearrangements in SLC26A3 mutated in congenital chloride diarrhea.
Congenital chloride diarrhea (CLD) is an autosomal recessive disorder characterized by defective intestinal electrolyte absorption, resulting in voluminous osmotic diarrhea with high chloride content. A variety of mutations in the solute carrier family 26, member 3 gene (SLC26A3, previously known as CLD or DRA) are responsible for the disease. Since the identification of the SLC26A3 gene and the determination of its genomic structure, altogether three founder and 17 private mutations have been characterized within miscellaneous ethnic groups. We screened for mutations in seven unrelated families with CLD. The diagnoses were confirmed by fecal chloride measurements. The combined PCR-SSCP and sequencing analyses revealed altogether seven novel mutations including two missense mutations (S206P, D468V), two splicing defects (IVS12-1G>C, IVS13-2delA), one nonsense mutation (Q436X), one insertion/deletion mutation (2104-2105delGGins29-bp), and an intragenic deletion of SLC26A3 exons 7 and 8. Two previously identified mutations were also found. This is the first report of rearrangement mutations in SLC26A3. Molecular features predisposing SLC26A3 for the two rearrangements may include repetitive elements and palindromic-like sequences. The increasingly wide diversity of SLC26A3 mutations suggests that mutations in the SLC26A3 gene may not be rare events.
Höglund
P
P
Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland. Pia.Hoglund@Helsinki.Fi
Sormaala
M
M
Haila
S
S
Socha
J
J
Rajaram
U
U
Scheurlen
W
W
Sinaasappel
M
M
de Jonge
H
H
Holmberg
C
C
Yoshikawa
H
H
Kere
J
J
D017920:Antiporters; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D027963:Chloride-Bicarbonate Antiporters; D002712:Chlorides / Q000378:metabolism*; D018389:Codon, Nonsense; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004252:DNA Mutational Analysis; D003967:Diarrhea / Q000151:congenital / Q000235:genetics*; D005192:Family Health; D017353:Gene Deletion; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D016254:Mutagenesis, Insertional; D009154:Mutation; D020125:Mutation, Missense; D011110:Polymorphism, Genetic; D018807:Polymorphism, Single-Stranded Conformational; D017384:Sequence Deletion; D000076988:Sulfate Transporters
D017920:Antiporters; D002352:Carrier Proteins; D027963:Chloride-Bicarbonate Antiporters; D002712:Chlorides; D018389:Codon, Nonsense; D008565:Membrane Proteins; C081011:SLC26A3 protein, human; D000076988:Sulfate Transporters; D004247:DNA