De novo 3q13.13q21.2 interstitial deletion and paternal 12p13.3 microdeletion in a fetus with dysplasia of the corpus callosum and ventriculomegaly: A case report.

Chromosome 3q syndrome is a well-known genetic condition caused by interstitial deletion in the long arm of chromosome 3. The phenotype of this syndrome is variable and the great variability in the extent of these deletions leads to a wide spectrum of clinical manifestations. Terminal 12p deletion represents one of the rarest subtelomeric imbalances; patients with distal monosomy 12p present different phenotypes ranging from muscular hypotonia to autism spectrum disorders. The present study reported a prenatal diagnosis of a male fetus presenting ultrasound evidence of corpus callosum dysplasia and ventriculomegaly showing a 3q13q21.2 deletion and a 12p13.33 microdeletion paternally inherited. Among several features previously attributed to the terminal deletion of 3q, corpus callosum dysplasia and ventriculomegaly have rarely been reported together. As the 12p13.33 microdeletion in the father was associated only with muscular hypotonia and joint laxity, the involvement of terminal 12p deletions in the clinical features of the fetus was not possible to verify during the prenatal period. The present case report may provide a reference for prenatal diagnosis and genetic counseling in patients who present 3q13q21.2 deletions and 12p13.33 microdeletion.

A new case of interstitial 1q 25.3-32.1 deletion: cytogenetic analysis molecular characterization and ultrasound findings.

INTRODUCTION: deletion of long arm of chromosome 1(1q-) is a rare condition. Clinical features include Dwarfism, severe mental retardation, microcephaly and short neck delineating the "intermediate 1q deletion syndrome". CASE REPORT: we report a new case of interstitial deletion of the long arm of chromosome 1, diagnosed in a 22+3 weeks gestation fetus in which cytogenetic analysis localized a loss of genetic materials of 18Mb in the 1q25.3-32.1. Fetal ultrasound showed neurodegenerative defects resembling Dandy-Walker's syndrome and bilateral clubfoot. CONCLUSIONS: clinical characteristics of our case are markedly mild. This suggests that the type and the extension of the mutation obtained through cytogenetic studies, CGH array and ultrasound evaluation should be taken into account for prognostic evaluation and management of these patients.

Discordance between karyotype from amniotic fluid and postnatal lymphocyte cultures.

Discordance between karyotype seen from amniocentesis and from neonatal blood is a very unusual condition with different possible causes.We present a case of discordance between prenatal cytogenetic diagnosis from amniotic fluid and post-natal cytogenetic diagnosis from lymphocyte cultures.