title: The (TAAAA)n polymorphism of sex hormone-binding globulin gene is not associated with testicular maldescent.
abstract: The aim of this family-based study was to investigate the potential association/genetic linkage of the (TAAAA)n polymorphism of sex hormone-binding globulin gene proximal promoter with testicular maldescent (TMD). Genomic DNA was extracted from the peripheral blood of 487 subjects (174 index families): (i) 180 children with all phenotypes of TMD, (ii) 307 parents (156 mothers and 151 fathers). Conventional polymerase chain reaction amplification products were electrophoresed on 10% nondenaturating polyacrylamide gel and visualised by silver staining. After excluding ambiguous parental-child trios and most cases of index families with missing parental genotypes, 429 individuals were left for analysis: 138 completely typed nuclear families (five included a second affected child) and five child-parent couples (one parent missing). Eight fathers presented history of TMD, that is, a total of 156 cases with TMD were analysed. Alleles were analysed with the affected family-based control method and logistic regression-based extension of the transmission disequilibrium test for multiallelic loci. (ΤΑΑΑΑ)n polymorphism analysis revealed six alleles based on repeat numbers (n=5-10). No association/genetic linkage between the (TAAAA)n polymorphism and TMD was detected. Other factors should be investigated to potentially explain the genetic predisposition that seems to exist in at least a subgroup of these patients.
authors.affiliation: Department of Urology, University of Crete, Medical School, Heraklion, Crete, Greece. c.mamoulakis@med.uoc.gr
authors.forename: C
authors.initials: C
authors.lastname: Mamoulakis
authors.forename: N
authors.initials: N
authors.lastname: Sofikitis
authors.forename: P
authors.initials: P
authors.lastname: Tsounapi
authors.forename: E
authors.initials: E
authors.lastname: Vlachopoulou
authors.forename: A
authors.initials: A
authors.lastname: Chatzikyriakidou
authors.forename: S
authors.initials: S
authors.lastname: Antypas
authors.forename: D
authors.initials: D
authors.lastname: Tzortzakakis
authors.forename: F
authors.initials: F
authors.lastname: Sofras
authors.forename: A
authors.initials: A
authors.lastname: Takenaka
authors.forename: I
authors.initials: I
authors.lastname: Georgiou
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003456:Cryptorchidism / Q000235:genetics* / Q000473:pathology; D004247:DNA / Q000097:blood; D005260:Female; D008040:Genetic Linkage; D020022:Genetic Predisposition to Disease; D006801:Humans; D007223:Infant; D008297:Male; D010290:Parents; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D012738:Sex Hormone-Binding Globulin / Q000235:genetics*
chemical_list: D012738:Sex Hormone-Binding Globulin; D004247:DNA