Map of the chromosome 3q DCMA candidate region. (A) Refined map interval spanning 23.9 cM from 3q26.2‐q27.3 between markers D3S1282 and D3S1262. The markers in bold represent the core disease associated region of approximately 2.2 Mb (see electronic database information section for uniSTS accession numbers). (B) An expanded map of the genomic organisation of the DNAJC19 gene. The six exons extend over 5.2 kb. The coding sequence is indicated in dark grey and the non‐coding sequence is in light grey. The locations of primers used for mutation screening are indicated. Primers used for amplification of three genomic segments are indicated by capital letters. Additional primers used for sequencing are shown in lower case. Primers used for reverse transcriptase polymerase chain reaction analysis are also indicated.

 The DNAJC19 IVS3‐1G→C mutation is associated with a dilated cardiomyopathy syndrome in consanguineous Hutterite families. (A) Patients and families included in this study show an extended common haplotype from D3S1282 to D3S1262; alleles included in this haplotype are highlighted in grey with the core disease associated region highlighted in dark grey. The genotypes for the DNAJC19 IVS3‐1G→C mutation are also shown. Patient numbers correspond with numbers in table 1. DNA was unavailable for patients 6 and 22; however, these patients were included in the study cohort, based on their clinical phenotypes. DNA for patient 25 was unavailable for haplotyping, but the clinical diagnosis was confirmed by genotyping for the DNAJC19 IVS3‐1G→C mutation at a later date. (B) Electropherograms showing DNAJC19 IVS3‐1G→C genotypes from an affected patient (C/C), an obligate carrier (G/C), and a wild type individual (G/G). These bases are reversed on the reverse sequence, as indicated below the figure.

 Expression analysis of DNAJC19. (A) Reverse transcriptase polymerase chain reaction (RT‐PCR) analysis of DNAJC19 using gene specific primers and RNA extracted from cultured fibroblasts from an affected patient and a non‐Hutterite normal control. Two bands were amplified from the normal control, one of 525 base pairs (bp) corresponding to the full length cDNA, and a second less abundant band of 445 bp. In the affected patient, only the 445 bp band was detected. The predicted size of the product from a DNAJC19 transcript missing the exon 4 coding sequence is 445 bp. (B) Expression analysis of DNAJC19 was undertaken using gene specific primers and various normalised first strand cDNA preparations from fetal and adult tissues. Both cDNAs were found expressed in all tissues, with the full length cDNA more abundant in all tissues tested except for adult leucocytes. Tissue types tested: bn, adult brain; co, adult colon; fb, fetal brain; fh, fetal heart; fk, fetal kidney; fl, fetal lung; flv, fetal liver; fsk, fetal skeletal muscle; fsp, fetal spleen; ft, fetal thymus; h, adult heart; k, adult kidney; l, adult lung; lk, adult leucocytes; lv, adult liver; ov, adult ovary; p, adult prostate; pa, adult pancreas; pl, placenta; si, adult small intestine; sk, adult skeletal muscle; sp, adult spleen; ts, adult testis; ty, adult thymus. Each set was run with G3PDH, glyceraldehyde‐3‐phosphate dehydrogenase control; C, positive control; b, water blank. (C) To determine the identity of the cDNA products, the 445 bp cDNA from the affected patient, the 445 bp and 525 bp bands from adult leucocytes were sequenced. Both the cDNA from the affected individual, and the 445 bp band from leucocytes were found to have exons 3 and 5 spliced together and the absence of exon 4 coding sequence (Δex4). The 525 bp band corresponded to the full coding sequence of DNAJC19. The Δex4 cDNA detected in normal tissues and control are thought to be a normal splice variant.

 DNAJC19 has an unusual domain architecture with respect to other DNAJ proteins and similar proteins are found in various species. (A) Graphical representation of the domain structure of H sapiens DNAJC19 v the E coli DNAJ/HSP40 protein. The DNAJC19 protein contains only the DNAJ domain (pfam00226.11), which is located at the C‐terminus following a predicted transmembrane domain. This is in contrast with the E coli DNAJ/HSP40 protein which is the classical example of a DNAJ protein. The DNAJ domain (pfam00226.11) is located at the N‐terminus of the protein followed by a glycine/phenylalanine‐rich linker domain, a cysteine‐rich domain (pfam00684.11) containing four copies of a zinc‐finger‐like motif (CXXCXGXG), and a C‐terminal domain (pfam01556.11) of unknown function. (B) ClustalW multiple sequence alignment of DNAJC19 homologues (see Electronic‐Database Information section for GenBank identification numbers). The conserved helix structures of the DNAJ domain are underlined; the DNAJ domains of these proteins only contain three of the helices that make up the classical tetrahelical DNAJ domain. They all also contain the absolutely conserved HPD motif which is indicated by (***). Highlighted regions indicate conserved blocks of sequence. Residues highlighted in black indicate positions with highest degree of conservation and those highlighted in grey indicate less highly conserved positions. Gaps introduced to optimise the alignment are indicated by dashes (–). Alignment was adjusted in Genedoc based on previously published alignments.