A missense mutation (R565W) in cirhin (FLJ14728) in North American Indian childhood cirrhosis - PubMed (original) (raw)

A missense mutation (R565W) in cirhin (FLJ14728) in North American Indian childhood cirrhosis

Pierre Chagnon et al. Am J Hum Genet. 2002 Dec.

Abstract

North American Indian childhood cirrhosis (CIRH1A, or NAIC), a severe autosomal recessive intrahepatic cholestasis described in Ojibway-Cree children from northwestern Quebec, is one of several familial cholestases with unknown molecular etiology. It typically presents with transient neonatal jaundice, in a child who is otherwise healthy, and progresses to biliary cirrhosis and portal hypertension. Clinical and physiological investigations have not revealed the underlying cause of the disease. Currently, liver transplantation is the only effective therapy for patients with advanced disease. We previously identified the NAIC locus by homozygosity mapping to chromosome 16q22. Here we report that an exon 15 mutation in gene FLJ14728 (alias Cirhin) causes NAIC: c.1741C-->T in GenBank cDNA sequence NM_032830, found in all NAIC chromosomes, changes the conserved arginine 565 codon to a tryptophan, altering the predicted secondary structure of the protein. Cirhin is preferentially expressed in embryonic liver, is predicted to localize to mitochondria, and contains WD repeats, which are structural motifs frequently associated with molecular scaffolds.

PubMed Disclaimer

Figures

Figure 1

Figure 1

Mutation detection. A, Electropherogram of patient (top), parent (middle), and control subject (bottom). At the bottom, the amino acid sequence corresponding to this DNA region is shown. The NAIC mutation changes an arginine codon to a tryptophan codon. B, Detection of the NAIC mutation by a PCR-RFLP test. The NAIC mutation creates an _Alu_I restriction site. Exon 15 of the FLJ14728 gene was amplified by PCR using forward primer 5′-AAT GCC CTT CTG GTC TTT CTG and reverse primer 5′-CGC AAA GTA GAC AAA TAG TCA. PCR was performed under the following conditions: 95°C for 5 min, followed by 35 cycles of 95°C for 45 s, 58°C for 30s, and 72°C for 45s. The amplicon was digested with _Alu_I, and the digestion products were separated on 3.0% agarose gels. The PCR fragment also contains a constant internal _Alu_I site that serves as a positive control for digestion and that yields a 150-bp fragment. Lanes 1–3, patients with NAIC; lanes 4–6, heterozygous parents; lanes 7–10, homozygous normal individuals.

Figure 2

Figure 2

Partial amino acid sequences of Cirhin and its homologues in vertebrates. The underlined arginine (R) is the residue mutated in patients with NAIC. Multiple sequence alignment was performed using the ClustalW alignment tool with Blosum weight matrix at the Baylor College of Medicine Search Launcher Web site. To generate the output, we used BoxShade 3.21 (BoxShade Server Web site). All homologous protein sequences (GenBank ID numbers shown) were originally identified by tblastn analysis at the NCBI BLAST Home Page, using the FLJ14728 protein sequence (GenBank accession number NP_116219 ) as a query against EST databases. In the residue numbering, 1 is the first amino acid in each of the predicted proteins.

Figure 3

Figure 3

Embryonic expression of Cirhin. In situ hybridization on a sagittal section of a day-11.5 mouse embryo with a 3′ probe showed prominent expression of Cirhin in the liver (arrow) and much weaker levels in the somites, brain, and craniofacial structures. Probe 1 specific to the 5′ portion of Cirhin gave identical results, whereas the corresponding sense probes showed no detectable signals. The mouse primer sequences for amplification by RT-PCR of probe 1 (5′ fragment of the gene) are 5′-CAG ATT GGC TGT TTC ACG AAC and TGT TGC CTA TCT AAA ACC ATC, and those for probe 2 (3′ fragment) are 5′-CTT TCC AGC CGC AGT CAG GTA and 5′-CCG CCT CAA GAA GAC ATC TGA T. Total adult mouse liver RNA was used as a template for the RT-PCRs.

Figure A

Figure A

A, Physical map of the NAIC critical region. All markers genotyped and all genes sequenced in the study are indicated (see the Electronic-Database Information section for a list of GenBank accession numbers). The region of homozygosity for all patients with NAIC is located between D16S3085 and D16S3095. The physical distance was based on the December 2001 browser of the Human Genome Working Draft (UCSC Genome Bioinformatics Web site). B, Structure and genomic organization of the Cirhin gene. The relative position of the Cirhin gene between HAS3 and SNTB2 is shown on BAC RP11-502K10 (GenBank accession number AC009131). Note that the arrows indicate the continuation of the BAC DNA and not the transcriptional polarity of the genes.

References

Electronic-Database Information

    1. Baylor College of Medicine Search Launcher: Multiple Sequence Alignments, http://searchlauncher.bcm.tmc.edu/multi-align/
    1. BoxShade Server, http://www.ch.embnet.org/software/BOX_form.html
    1. ExPASy Molecular Biology Server, http://ca.expasy.org/
    1. GenBank, http://www.ncbi.nlm.nih.gov/Genbank (for hypothetical protein FLJ14728 [accession number NM_032830], CA7 [accession number NM_005182], DNCLI2 [accession number NM_006141], CES2 [accession number NM_003869], TRADD [accession number NM_003789], SLC9A5 [accession number NM_004594], HSD11B2 [accession number NM_000196], ATP6DV [accession number X71490], CTCF [NM_006565], PSMB10 [accession number NM_002801], LCAT [accession number NM_000229], NFATC3 [accession number NM_004555], SMPD3 [accession number NM_018667], CDH3 [accession number NM_001793], CDH1 [accession number NM_004360], hypothetical protein FLJ12688 [accession number AK022750], HAS3 [accession number NM_005329], SNTB2 [accession number NM_006750], VPS4 [accession number NM_013245], LOC64146 [accession number NM_022341], hypothetical protein HSPC031 [accession number NM_016101], TERF2 [accession number NM_005652], CYB5-M [accession number NM_030579], DIA4 [accession number NM_000903], TAT [accession number NM_000353], DHODH [accession number M94065], PRP16 [accession number NM_014003], Homo sapiens chromosome 16 clone RP11-502K10 [accession number AC009131], and YDR324Cp [accession number AAB64760; GI:915001])
    1. iPSORT Home Page, http://www.hypothesiscreator.net/iPSORT/

References

    1. Arnell H, Nemeth A, Anneren G, Dahl N (1997) Progressive familial intrahepatic cholestasis (PFIC): evidence for genetic heterogeneity by exclusion of linkage to chromosome 18q21-q22. Hum Genet 100:378–381 - PubMed
    1. Betard C, Rasquin-Weber A, Brewer C, Drouin E, Clark S, Verner A, Darmond-Zwaig C, Fortin J, Mercier J, Chagnon P, Fujiwara TM, Morgan K, Richter A, Hudson TJ, Mitchell GA (2000) Localization of a recessive gene for North American Indian childhood cirrhosis to chromosome region 16q22—and identification of a shared haplotype. Am J Hum Genet 67:222–228 - PMC - PubMed
    1. Bull LN, van Eijk MJ, Pawlikowska L, DeYoung JA, Juijn JA, Liao M, Klomp LW, Lomri N, Berger R, Scharschmidt BF, Knisely AS, Houwen RH, Freimer NB (1998) A gene encoding a P-type ATPase mutated in two forms of hereditary cholestasis. Nat Genet 18:219–224 - PubMed
    1. Camacho JA, Obie C, Biery B, Goodman BK, Hu CA, Almashanu S, Steel G, Casey R, Lambert M, Mitchell GA, Valle D (1999) Hyperornithinaemia-hyperammonaemia-homocitrullinuria syndrome is caused by mutations in a gene encoding a mitochondrial ornithine transporter. Nat Genet 22:151–158 - PubMed
    1. Chen HL, Chang PS, Hsu HC, Lee JH, Ni YH, Hsu HY, Jeng YM, Chang MH (2001) Progressive familial intrahepatic cholestasis with high γ-glutamyltranspeptidase levels in Taiwanese infants: role of MDR3 gene defect? Pediatr Res 50:50–55 - PubMed

MeSH terms

Substances

LinkOut - more resources