Segregation analysis of rare autosomal folate sensitive fragile sites

Abstract

We have studied 12 families with rare autosomal folate sensitive fragile sites (RAFSFS). Of these, 9 were informative for segregtion analysis of fragile sites in order to assess differences in parental transmission. We identified 20 families with RAFSFS from the literature from 1985 to 1989; thirteen of these were informativ for segregation analysis. Segregation analysis confirmed that paternal fragile site transmission rates deviated significantly from the expected 50% for a Mendelian co‐dominant trait. Sex ratio comparisons showed a significant excess of transmitting females and a significnt excess of males among fragile site non‐carriers from the literature families. Comparison of the fragile site carriers with non‐carriers in the combined data showed a non‐significant excess of non‐carriers. We confirmed a deficiency of offspring expressing fragile sites when trnsmission was through fathers, suggesting gametic selection or the phenomenon of parental genomic imprinting. © 1993 Wiley‐Liss, Inc.

Diagnostic yield in the clinical genetic evaluation of autism spectrum disorders

“…Some (2q13, 6p23, 12q13) have only been reported in autistic individuals. [92][93][94] This study affirms previous documentation of the utility of a comprehensive clinical genetic evaluation of individuals with the diagnosis of autism. Recent studies indicate that such evaluations are even applicable across the milder aspects of the spectrum of pervasive developmental disorders.…”

Prenatal diagnosis of FRA10A: A case report and literature review

“…This study is also in agreement with others that have suggested that FRA10A is expressed 100% of the time when transmitted by the mother. However, this limited pedigree did not allow for demonstration of the significant deviation, from the expected 50% for a Mendelian co‐dominant trait, that has been reported for this fragile site when inherited from the father [Sherman and Sutherland, 1986; Samadder et al, 1993].…”

Localization of Fragile Sites in the Karyotype of Sus scrofa domestica: Present Status

“…Some fragile sites are transmitted as co-dominant traits (SUTHERLAND and HECHT 1985;HECHT 1986HECHT , 1988a, but the precise transmission of all fragile sites is not known. Segregation analysis of rare autosomal folate sensitive fragile sites suggests that when transmitted through fathers, gametic selection or parental genomic imprinting may be involved (SAMADDER et al 1993).…”