A TURNER SYNDROME WOMAN WITH A RING X-CHROMOSOME [45,X 46,X,R(X)(P22.3Q27)] WHOSE CHILD ALSO HAD A RING X-CHROMOSOME/

Objective: To describe a woman with Turner syndrome with ring X chromo some mosaicism who had a child who possessed the same ring X chromosom e. Design: Polymorphisms of genes located on the X chromosome from gen omic DNA of the mother, father, and the child were evaluated. Patient( s): The mother's karyotype was 45,X [48]/46,X,r(X)(p22.3q27) [2], and the child's karyotype was 45,X [33]/46,X,r(X)(p22.3q27) [17]. Interven tion(s): Polymerase chain reaction was used to amplify short tandem re peats from the loci of the hypoxanthine phosphoribosyltransferase gene and the androgen receptor gene. Result(s): Alleles for both genes in the child originated from both parents in a heterozygous fashion. The alleles originating from the mother originated from the ring X chromos ome. However, the amount of amplified DNA was less than that of a norm al X chromosome. Conclusion(s): The ring X chromosome of the mother wa s most likely transmitted to the newborn. Thus, an ovum with the ring X chromosome can be fertile and can produce a viable zygote.