title: DNA linkage based diagnosis of Wilson disease in asymptomatic siblings.
abstract: OBJECTIVE
  Wilson disease (WD) is an autosomal recessive disorder caused by defects in ATP7B gene located in chromosome 13q14, and manifested as hepatolenticular degeneration as a result of accumulation of copper. No information on the mutation in the ATP7B gene and haplotypes using linked markers is available for WD patients in India. Hence, the present study was undertaken to identify, by a PCR-based molecular diagnostic test, presymptomatic siblings of WD affected individuals in families with multiple offspring.
  
  
  METHODS
  Genomic DNA was prepared from the peripheral blood of the patients, siblings and his/her first degree relatives. The repeat-markers flanking WD locus were amplified by PCR using fluorescent labeled primers. Amplified DNA fragments were analyzed by polyacrylamide gel electrophoresis in ABI 377 DNA sequencing system. Genotypes of the samples were determined using Genescan software. Haplotypes were determined based on segregation of the alleles in the families under study.
  
  
  RESULTS
  Among 15 WD affected families with multiple children, 4 cases were identified where younger siblings shared same genotype as the patient at all three markers analyzed. Further, eight different haplotypes were detected in the four patients.
  
  
  CONCLUSIONS
  The siblings of the WD patients carrying the same genotype at the markers linked to WD locus were presymptomatically diagnosed individuals. Presence of eight different haplotypes in the four patients suggested mutational heterogeneity at the WD locus. The test helps clinicians for therapeutic intervention in suspect WD cases by copper chelating agents prior to manifestation of overt clinical symptoms.
authors.affiliation: Human Genetics & Genomics Division, Indian Institute of Chemical Biology, Jadavpur, Kolkata, India.
authors.forename: A
authors.initials: A
authors.lastname: Gupta
authors.forename: R
authors.initials: R
authors.lastname: Neogi
authors.forename: M
authors.initials: M
authors.lastname: Mukherjea
authors.forename: A
authors.initials: A
authors.lastname: Mukhopadhyay
authors.forename: S
authors.initials: S
authors.lastname: Roychoudhury
authors.forename: A
authors.initials: A
authors.lastname: Senapati
authors.forename: P K
authors.initials: PK
authors.lastname: Gangopadhyay
authors.forename: Kunal
authors.initials: K
authors.lastname: Ray
mesh_terms: D000293:Adolescent; D005260:Female; D008040:Genetic Linkage; D005820:Genetic Testing; D006527:Hepatolenticular Degeneration / Q000175:diagnosis* / Q000235:genetics*; D006801:Humans; D008297:Male; D010375:Pedigree; D035781:Siblings