A rare case: mosaic trisomy 22.

A 9-year-old female child of healthy parents (mother: 43 years, father: 44 years) was referred to our center because of severe mental retardation. While pedigree analysis was not contributory, two older sibs were normal and healthy. Physical examination revealed facial dysmorphism, microcephaly and hyperflexibility of all joints. Her chromosome constitution showed a mosaic pattern; mos 46,XX[98]/47,XX,+22[2]. So skin biopsy was performed and mosaic trisomy 22 was confirmed with FISH analysis (46,XX[73]/47,XX,+22[27]). Physical features of this case seemed consistent with her mosaic constitution. This report would be a demonstrative example to show the significant contribution of FISH in states of mosaicism.

Double meningocele. Case report.

The coexistence of two distinct meningoceles of the spine is a very unusual event. We report a three-day-old boy with double meningoceles at the thoracic and lumbar levels. The connection between the stalk of the thoracic meningocele and the spinal cord, as seen on magnetic resonance imaging, showed a neurological involvement in this lesion. Our case is only the third without association of congenital anomalies or neurofibromatosis to be reported to date.

FISH analysis with locus-specific probes in sperm from two translocation carrier men.

Meiotic segregation of normal and derivative chromosomes was analysed in sperm samples from two balanced reciprocal translocation carrier men by use of dual-colour fluorescence in situ hybridisation (FISH) technique. The translocations were t(4;8)(p15;p12) and t(15;22)(q(23:q13.2), and the digoxigenin-labelled FISH probes were specific to either the translocated or centric segments of the chromosomes involved in the translocations. A total of 1000 spermatozoa for each probe were analysed and the modes of segregation were described on the basis of signals in each sperm cell. The mean frequency of alternate and/or adjacent-1 (adj-1) segregation types was 69.47%, whereas they were 30.51 and 78.70% for the adjacent-2 (adj-2) and alternate/adj-2 segregation types, respectively. This study illustrated that FISH is a valuable technique for analysing the meiotic segregation products of the heterozygotes in respect to aneuploidy risk.

The deletion of 22q13 region in both intracranial and spinal meningiomas in a patient (case report).

We present a 69 year old man with two simultaneous meningiomas in different compartment of neural axis, in both of which 22q13 locus is lost. Histologically the two tumours appeared to be different; meningotheliomatous and transitional with psammoma bodies, respectively. No numerical or structural chromosome abnormalities were seen in karyotype analysis of the cultured spinal and cranial meningioma samples. Since long arm structural aberrations and/or whole loss of chromosome 22 are frequently reported abnormalities of meningiomas, the tumours were also analysed by fluorescence in situ hybridisation (FISH) with different colour-labelled probes in respect to relevant chromosome. The metaphases and interphase nuclei of the samples were evaluated by the combined biotinylated 22q11 and digoxigenin-labelled 22q13 locus specific FISH probes, and 22q13 deletion was revealed in both of spinal and cranial tumour cells. In conclusion, since both tumours from the presented case show the same genetic alterations, multiplicity may be derived from the same clone of cells, and support the theory of development of multiple meningiomas from the spreading of tumour cells via cerebrospinal fluid as a possible mechanism.