Algorithm for efficient PKHD1 mutation screening in autosomal recessive polycystic kidney disease (ARPKD).
Autosomal recessive polycystic kidney disease (ARPKD) is an important cause of childhood renal- and liver-related morbidity and mortality with variable disease expression. While most cases manifest peri-/neonatally with a high mortality rate in the first month of life, others survive to adulthood. ARPKD is caused by mutations in the Polycystic Kidney and Hepatic Disease 1 (PKHD1) gene on chromosome 6p12. PKHD1 is an exceptionally large gene (470 kb) with a longest open reading frame transcript of 67 exons predicted to encode a 4,074-amino acid (aa) (447 kDa) multidomain integral membrane protein (fibrocystin/polyductin) of unknown function. Recent DHPLC-based mutational studies have reported detection rates of about 80% and a minimum of one PKHD1 mutation in more than 95% of families. Thus far, a total of 263 different PKHD1 mutations (639 mutated alleles) are included in the locus-specific database (www.humgen.rwth-aachen.de). Except for a few population-specific founder alleles and the common c.107C>T (p.Thr36Met) missense change, PKHD1 is characterized by significant allelic diversity, making mutation screening time-consuming and labor-intensive. Mutations are distributed throughout the gene's coding sequence; however, they are not equally scattered. Thus, we aimed to set up an algorithm for efficient molecular genetic diagnostics in ARPKD. A total of 80% of known PKHD1 mutations can be identified if a subset of 27 out of 77 DHPLC fragments is screened. The current study provides an essential platform for PKHD1 mutation screening in a routine setting that will largely alleviate molecular genetic diagnostics in patients suspected to have ARPKD.
Bergmann
Carsten
C
Department of Human Genetics, Aachen University, Aachen, Germany. cbergmann@ukaachen.de <cbergmann@ukaachen.de>
Küpper
Fabian
F
Dornia
Christian
C
Schneider
Frank
F
Senderek
Jan
J
Zerres
Klaus
K
D000465:Algorithms; D000483:Alleles; D002851:Chromatography, High Pressure Liquid; D015331:Cohort Studies; D004252:DNA Mutational Analysis / Q000379:methods*; D016208:Databases, Factual; D005808:Genes, Recessive; D005820:Genetic Testing / Q000379:methods*; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D016366:Open Reading Frames / Q000235:genetics; D017044:Polycystic Kidney, Autosomal Recessive / Q000235:genetics*; D011956:Receptors, Cell Surface / Q000235:genetics*; D012680:Sensitivity and Specificity; D044465:White People / Q000235:genetics
C451750:PKHD1 protein, human; D011956:Receptors, Cell Surface