Search

Here we describe clinical and cytogenetic data on a female child whom had been referred to our laboratory suspected to have Turner syndrome since she had webbed neck. Cytogenetic analysis revealed that she had deletion at 11q23.2 to 11q terminal so her karyotype was ascertained as 46,XX,del(11)(q23.2). Her parents had normal karyotypes. In addition to many clinical features of del(11q ) syndrome the case had poor vision which is not common for this syndrome. Clinical features of this case and a few published cases will be reviewed briefly.

We report a neonate with pure deletion of distal 11q (11q23.3-->qter) and Jacobsen syndrome. The patient had growth restriction, petechiae, thrombocytopenia, dilation of renal pelvis, congenital heart defects, and seizures. Array comparative genomic hybridization revealed a 15.8-Mb deletion from 11q23.3 to 11q25 without genomic imbalances in other chromosomes. Cytogenetic analysis revealed a karyotype of 46,XX,der(7)(7pter-->7q32),der(11)(11pter--> 11q23.3::7q32-->7qter). The parental karyotypes were normal. This is the first report of pure distal 11q deletion without additional genomic imbalances in a patient with Jacobsen syndrome and a de novo unbalanced reciprocal translocation.

Jacobsen syndrome is a rare disorder, caused by segmental monosomy for the distal end of the long arm of chromosome 11 with variable phenotypic expressivity. We report on the first male (6 years old) and female (3 years old) sibs with clinical and cytogenetics characterization of Jacobsen syndrome. Their karyotypes showed deletion 11q23.3-qter. Patients presented with growth and psychomotor retardation, facial dysmorphism, eye anomalies, and congenital heart disease (variable degrees of septal defect). Family history revealed a clinically similar brother, who died at 2 months old from cardiac anomalies in the form of single ventricle without being subjected to further investigations. Chromosomal analysis of the parents was normal. Karyotyping for the 2 patients and their parents was confirmed by fluorescence in situ hybridization analysis (FISH) using whole chromosome painting probes for 11 (WCP 11). Relevant investigations for both sibs showed mild thrombocytopenia with normal platelets morphology and striking periventricular demyelination on neuroimaging. Inguinal small testicles as well as focal epileptiform dysfunction were recorded in the male patient only. Abdominal ultrasound, hearing test, and DEXA scan were normal in both patients. Due to of the presence of apparently 3 affected offspring and normal parental karyotypes, an inherited predisposition was highly suspected. The large size of the distal deleted 11q segment in our patients support the recent hypothesis, that Jacobsen syndrome is a chromosomal deletion syndrome with genetic predisposition, due to expansion of p(CCG)n trinucleotide in the folate-sensitive fragile site FRA11B, at breakpoint 11q23.3. In conclusion, identification and further delineation of more similar patients will contribute to understanding the genetic basis of the 11q phenotype.