Terminal deletions of the long arm of chromosome X that include the FMR1 gene in female patients: a case series.

Terminal deletions on the X chromosome in female patients may be detected as part of a work up for infertility, premature ovarian insufficiency (POI) or in screening for fragile X carrier status. We present the clinical, cytogenetic and molecular features of four patients with terminal deletions of chromosome X that include the FMR1 gene, and discuss biological and genetic implications of this deletion. Providers should be aware of possible identification of Xq27 deletions as a potential outcome of fragile X screening.

Hypophosphatasia: molecular testing of 19 prenatal cases and discussion about genetic counseling.

Objective: We studied hypophosphatasia (HP) mutations in 19 cases prenatally detected by ultrasonography without familial history of HP. We correlated the mutations with the reported ultrasound signs, and discussed genetic counseling with regard to the particular dominantly inherited prenatal benign form of HP.

Method: The coding sequence of the tissue nonspecific alkaline phosphatase (TNSALP) gene was analyzed by DNA sequencing, and 3D modeling was used to locate the mutated amino acids with regard to the functional domains of TNSALP.