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 chromosome mosaicism who had a child who possessed the same ring X chromosome.

DESIGN

Polymorphisms of genes located on the X chromosome from genomic 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].

INTERVENTION(S): Polymerase chain reaction was used to amplify short tandem repeats 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 chromosome. However, the amount of amplified DNA was less than that of a normal X chromosome.

CONCLUSION(S): The ring X chromosome of the mother was most likely transmitted to the newborn. Thus, an ovum with the ring X chromosome can be fertile and can produce a viable zygote.