Familial inversion translocation (8;13) with partial trisomy 13 in several family members

Partial Trisomy of Chromosome 13 with a Novel Translocation (8 ; 13) and Unique Clinical Presentation in a Palestinian Infant

Partial trisomy 13 is a rare syndrome that usually culminates in death within the first six months of the infant's life. We present a rare case of partial trisomy 13q with exclusive clinical manifestations. The full-term male baby was born by normal vaginal delivery, his birth weight was 3500 grams, and head circumference was 30 cm. He had dysmorphic features in the form of microcephaly, trigonocephaly, depressed nose bridge, hypotelorism, long philtrum, high arch palate, left-sided inguinal hernia, hydrocele, and laryngomalacia. He was operated for pyloric stenosis at the age of 28 days. He also had left-sided severe pelvic-ureteral junction stenosis which was repaired by nephrostomy followed by pyeloplasty. Furthermore, he had right-sided vesicoureteral reflux grade III, right-sided hydronephrosis, small ventricular septum defect, small atrial septum defect, left lung lower lobe sequestration, and craniosynostosis of metopic suture. The baby had global developmental delay and failure to thrive. Cytogenetic study showed a 46,XY, der(8)t(8;13)(p23;q14) karyotype, emphasizing a partial trisomy 13q syndrome with a concomitant partial monosomy in 8p. The baby passed away, in the intensive care unit, at the age of 7 months due to respiratory failure resulting from recurrent chest infections. This is the first reported case of a partial trisomy 13q associated with chromosome 8 with unique clinical presentations. Cytogenetic study for both parents is recommended in order to pinpoint the origin of the translocation and to provide the proper counseling for the family.

De novo duplication of chromosome 13(q32-q34) in a child with developmental delay

We report the case of a child affected by a duplication of chromosome 13(q32-q34). This cytogenetic abnormality is rarely described in the literature. The description of our patient's characteristics might contribute to a better phenotype definition.

Characterization of a familial balanced rec(13) in a child with mild MR and his half-sibling with two structurally rearranged chromosomes 13

In this report, we describe a 7-year-old child with mild mental retardation, developmental delay, and learning disabilities. His karyotype contained a rearrangement of chromosome 13, which appeared to include a duplication of 13q31-qter and a deletion of 13p12-pter regions. The chromosomal origin of the additional material was confirmed by fluorescence in situ hybridization (FISH) using a whole chromosome painting probe specific for chromosome 13. Family studies showed that his mother carried a balanced inversion of chromosome 13 and that his half-brother carried the balanced pericentric inversion of chromosome 13 from his mother as well as another structural rearrangement involving chromosome 13 presumably from his father. The findings from this study suggested that the proband's abnormal 13 resulted from an unbalanced crossing-over between the normal and maternal inverted chromosome 13.

Chromosomal abnormalities and epilepsy: a review for clinicians and gene hunters

PURPOSE

We analyzed databases on chromosomal anomalies and epilepsy to identify chromosomal regions where abnormalities are associated with clinically recognizable epilepsy syndromes. The expectation was that these regions could then be offered as targets in the search for epilepsy genes.

METHODS

The cytogenetic program of the Oxford Medical Database, and the PubMed database were used to identify chromosomal aberrations associated with seizures and/or EEG abnormalities. The literature on selected small anomalies thus identified was reviewed from a clinical and electroencephalographic viewpoint, to classify the seizures and syndromes according to the current International League Against Epilepsy (ILAE) classification.

RESULTS

There were 400 different chromosomal imbalances described with seizures or EEG abnormalities. Eight chromosomal disorders had a high association with epilepsy. These comprised: the Wolf-Hirschhorn (4p-) syndrome, Miller-Dieker syndrome (del 17p13.3), Angelman syndrome (del 15q11-q13), the inversion duplication 15 syndrome, terminal deletions of chromosome 1q and 1p, and ring chromosomes 14 and 20. Many other segments had a weaker association with seizures. The poor quality of description of the epileptology in many reports thwarted an attempt to make precise karyotype-phenotype correlations.

CONCLUSIONS

We identified certain chromosomal regions where aberrations had an evident association with seizures, and these regions may be useful targets for gene hunters. New correlations with specific epilepsy syndromes were not revealed. Clinicians should continue to search for small chromosomal abnormalities associated with specific epilepsy syndromes that could provide important clues for finding epilepsy genes, and the epileptology should be rigorously characterized.

Phenotype-karyotype correlation in patients trisomic for various segments of chromosome 13

Analysis of clinical and cytogenetic findings taken from 62 published cases of partial trisomies of chromosome 13 showed that 15 had partial trisomy for the proximal long arm and 47 had trisomy for the distal long arm. Persistence of fetal haemoglobin (Hb F), increased projections of polymorphonuclear leucocytes (PMN), depressed nasal bridge, cleft lip/palate, and clinodactyly were more frequent in patients with proximal trisomy 13. In the distal trisomy group, the common features included haemangioma, bushy eyebrows, long curled eyelashes, prominent nasal bridge, long philtrum, thin upper lip, highly arched palate, and hexadactyly. In addition, several other features were common to both the groups, often showing inconsistency even when the same segment was in trisomy. The influence of the second aneusomy as the most likely cause for such inconsistent and overlapping phenotypes is discussed in view of the fact that 42 of 62 cases were derived from a balanced translocation carrier parent.