title: Identification of a null allele in genetic tests for bovine leukocyte adhesion deficiency in Pakistani Bos indicus × Bos taurus cattle.
abstract: Two clinically healthy mature Pakistani Bos indicus × Bos taurus cattle were genotyped as homozygous affected for the lethal immunodeficiency disorder bovine leukocyte adhesion deficiency (BLAD) using previously described PCR-RFLP based DNA tests which was confirmed by sequencing. Sequencing of Bos taurus and B. indicus × B. taurus genomic DNA surrounding the disease causing mutation (c.383A > G) in the ITGB2 gene identified numerous variations in exonic and intronic regions within and between species, including substantial variation in primer annealing sites for three PCR-RFLP tests for one of the B. indicus allelic variants. These variations in the primer annealing sites resulted in a null allele in the DNA tests causing the misdiagnosis of some heterozygous B. taurus × B. indicus cattle to be classified as homozygous affected. New primers were designed and a modified test was developed which simultaneously identified the disease mutation and the Pakistani B. indicus allelic variant associated with the null allele in the previous test.
authors.affiliation: Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, P.O. Box 577, Jhang Road, Faisalabad, Pakistan. fozianasreen@gmail.com
authors.forename: Fozia
authors.initials: F
authors.lastname: Nasreen
authors.forename: Naveed A
authors.initials: NA
authors.lastname: Malik
authors.forename: Javed A
authors.initials: JA
authors.lastname: Qureshi
authors.forename: Herman W
authors.initials: HW
authors.lastname: Raadsma
authors.forename: Imke
authors.initials: I
authors.lastname: Tammen
mesh_terms: D000483:Alleles; D054458:Amplified Fragment Length Polymorphism Analysis; D000818:Animals; D001483:Base Sequence; D018821:CD18 Antigens / Q000235:genetics; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis / Q000235:genetics*; D056726:Genetic Association Studies; D005820:Genetic Testing; D018370:Leukocyte-Adhesion Deficiency Syndrome / Q000175:diagnosis / Q000235:genetics / Q000662:veterinary*; D008297:Male; D025202:Molecular Diagnostic Techniques; D008969:Molecular Sequence Data; D010154:Pakistan; D017422:Sequence Analysis, DNA
chemical_list: D018821:CD18 Antigens