Familial pericentric inversion of chromosome 18: intrafamilial variability of the recombinant dup(18q).

A pericentric inversion of chromosome 18 [inv(18)(p11.32q22)] and its recombinants has been studied in a three-generation family. A mother/son couple, carrying the rec dup(18q), showed dysmorphisms and short stature but only the son had mild mental retardation and speech delay.

Paracentric inversion of Yq and review of the literature.

We report on the second prenatal diagnosis of familial paracentric inversion of the long arm of Y chromosome [46, X, inv(Y)(q11.2q12)]. The anomaly was detected through an amniocentesis performed because of advanced maternal age.

Cytogenetic and array CGH characterization of an intrachromosomal complex rearrangement of 4q in a patient with a 4q-phenotype.

We report on a 3-year-old child who presented a de novo rearrangement of chromosome 4, detected on GTG banding and characterized by array CGH and FISH, as a complex intrachromosomal rearrangement with three deletions: del(q32.1q32.2), del(q33q34.

Prenatal diagnosis of a de novo satellited chromosome 18 (18ps) associated with 18p deletion.

De novo satellited non-acrocentric chromosomes are very rare findings in prenatal diagnosis. Here we report the first case of a de novo 18ps, associated with del(18p), detected at prenatal diagnosis. A 37 years old woman underwent Chorionic Villus Sampling (CVS) for advanced maternal age.

Trisomy 15 mosaicism owing to familial reciprocal translocation t(1;15): implication for prenatal diagnosis.

We describe a 4-year-old female child with severe global mental retardation, myoclonic epilepsy, proximal hypotonia and dysmorphisms, whose prenatal diagnosis following amniocentesis revealed a constitutional female karyotype carrying a t(1;15)(q10;p11) familial reciprocal translocation. Post-natal high-resolution karyotype, Fluorescence in situ hybridization (FISH) screening for subtelomeric rearrangements, VNTR search for UPD15 in the blood and fibroblast, and WCP1 and 15 in the mother, failed to provide an explanation for the complex clinical phenotype of the proband. Since the pachytene configuration of the translocated chromosomes defines a high probability of 3:1 segregation, an extensive workup was undertaken to look for a possibly cryptic mosaicism.