title: Linkage analysis of a large African family segregating stuttering suggests polygenic inheritance.
abstract: We describe a pedigree of 71 individuals from the Republic of Cameroon in which at least 33 individuals have a clinical diagnosis of persistent stuttering. The high concentration of stuttering individuals suggests that the pedigree either contains a single highly penetrant gene variant or that assortative mating led to multiple stuttering-associated variants being transmitted in different parts of the pedigree. No single locus displayed significant linkage to stuttering in initial genome-wide scans with microsatellite and SNP markers. By dividing the pedigree into five subpedigrees, we found evidence for linkage to previously reported loci on 3q and 15q, and to novel loci on 2p, 3p, 14q, and a different region of 15q. Using the two-locus mode of Superlink, we showed that combining the recessive locus on 2p and a single-locus additive representation of the 15q loci is sufficient to achieve a two-locus score over 6 on the entire pedigree. For this 2p + 15q analysis, we show LOD scores ranging from 4.69 to 6.57, and the scores are sensitive to which marker is chosen for 15q. Our findings provide strong evidence for linkage at several loci.
authors.affiliation: National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA.
authors.forename: M Hashim
authors.initials: MH
authors.lastname: Raza
authors.forename: E Michael
authors.initials: EM
authors.lastname: Gertz
authors.forename: Jennifer
authors.initials: J
authors.lastname: Mundorff
authors.forename: Joseph
authors.initials: J
authors.lastname: Lukong
authors.forename: Judith
authors.initials: J
authors.lastname: Kuster
authors.forename: Alejandro A
authors.initials: AA
authors.lastname: Schäffer
authors.forename: Dennis
authors.initials: D
authors.lastname: Drayna
mesh_terms: D044383:Black People / Q000235:genetics*; D002163:Cameroon; D002884:Chromosomes, Human, Pair 15 / Q000235:genetics*; D002893:Chromosomes, Human, Pair 3 / Q000235:genetics; D005190:Family; D005260:Female; D056426:Genetic Loci; D005819:Genetic Markers; D006801:Humans; D008126:Lod Score; D008297:Male; D008875:Middle Aged; D020412:Multifactorial Inheritance; D020641:Polymorphism, Single Nucleotide; D013342:Stuttering / Q000235:genetics*
chemical_list: D005819:Genetic Markers