Array-based comparative genomic hybridization identifies a high frequency of copy number variations in patients with syndromic overgrowth.

Overgrowth syndromes are a heterogeneous group of conditions including endocrine hormone disorders, several genetic syndromes and other disorders with unknown etiopathogenesis. Among genetic causes, chromosomal deletions and duplications such as dup(4)(p16.3), dup(15)(q26qter), del(9)(q22.

Familial interstitial Xq27.3q28 duplication encompassing the FMR1 gene but not the MECP2 gene causes a new syndromic mental retardation condition.

X-linked mental retardation is a common disorder that accounts for 5-10% of cases of mental retardation in males. Fragile X syndrome is the most common form resulting from a loss of expression of the FMR1 gene. On the other hand, partial duplication of the long arm of the X chromosome is uncommon.

Maternal uniparental heterodisomy of chromosome 17 in a patient with nephropathic cystinosis.

We report maternal uniparental disomy of chromosome 17 (mat UPD17) in a 2.5-year-old girl presenting infantile cystinosis. This patient was homozygous for the 57 kb deletion encompassing the CTNS gene, frequently found in patients from the European origin.

Cytogenetic and histological features of a human embryo with homogeneous chromosome 8 trisomy.

Background: Homogeneous and complete trisomy 8 is extremely rare. With one recent neonatal exception, all reported cases have been mosaic, due to mitotic non-disjunction during early zygotic development. We report a case of chromosome 8 trisomy in a human embryo examined at Carnegie stage 11 (25 days post-fertilization).

Molecular characterisation of a prenatally diagnosed 5q15q21.3 deletion and review of the literature.

Background: Ultrasound examination performed on a 32-year old woman at 30 weeks' gestation showed the presence of fetal malformations. Amniocentesis was performed.

Methods And Results: Cytogenetic analysis of cultured amniocytes revealed an interstitial deletion of the long arm of chromosome 5.

Functional disomy of the Xq28 chromosome region.

We report on two patients, a boy and a girl, with an additional Xq28 chromosome segment translocated onto the long arm of an autosome. The karyotypes were 46,XY,der(10)t(X;10)(q28;qter) and 46,XX,der(4)t(X;4)(q28;q34), respectively. In both cases, the de novo cryptic unbalanced X-autosome translocation resulted in a Xq28 chromosome functional disomy.

Molecular screening of the ZFHX1B gene in prenatally diagnosed isolated agenesis of the corpus callosum.

Objective: Agenesis of the corpus callosum (ACC) is the most common malformation of the central nervous system and may be associated with mental retardation. ACC is found in 40% of the cases of Mowat-Wilson syndrome (MWS), a polytopic embryonic defect including a distinctive facial gestalt, severe mental retardation, epilepsy and postnatal microcephaly as constant features. Other manifestations involve Hirschsprung disease, cardiac defects, renal abnormalities and hypospadias.

Reproductive genetic counselling in non-mosaic 47,XXY patients: implications for preimplantation or prenatal diagnosis: Case report and review.

With an incidence of approximately 1 in 500 male newborns, the 47,XXY genotype is one the most common sex chromosome anomalies. It is also the most frequent genetic cause of human infertility. Some non-mosaic 47,XXY patients have sperm production which allows infertility treatment to be offered by ICSI.