An unbalanced submicroscopic translocation t(8;16)(q24.3;p13.3)pat associated with tuberous sclerosis complex, adult polycystic kidney disease, and hypomelanosis of Ito

Abstract

We report on a familial submicroscopic translocation involving chromosomes 8 and 16. The proband of the family had a clinical picture suggestive of a large deletion in the chromosome 16p13.3 area, as he was aVected with tuberous sclerosis complex (TSC) and had thalassaemia trait, and his half brother, who also had TSC, may have suVered additionally from polycystic kidney disease (PKD). FISH studies provided evidence for a familial translocation t(8;16)(q24.3;p13.3) with an unbalanced form in the proband and a balanced form in the father and in a paternal aunt.The unbalanced translocation caused the index patient to be deleted for the chromosome 16p13.3-pter region, with the most proximal breakpoint described to date for terminal 16p deletions. In addition, FISH analysis showed a duplication for the distal 8q region. Since the index patient also had hypomelanosis of Ito (HI), either of the chromosomal areas involved in the translocation may be a candidate region for an HI determining gene. Furthermore, it is noteworthy that both carriers of the balanced translocation showed a nodular goitre, while the proband has hypothyroidism. (J Med Genet 2000;37:287-291)

Delineation of complex chromosomal rearrangements: evidence for increased complexity

“…Subsequent FISH analysis of several BACs revealed a far more complex karyotype, with subtelomeric rearrangements involving 16p, 17p, and 20q, an insertion of approximately 9 Mb of 16p (16p13.13 to 16p12.2) into 4p16.3, a small reciprocal insertion of 4p16.3 material into 16p, a second small insertion of 16p13.3 into 4p, and a cryptic deletion of 0.8 Mb in 16p13.3. There have been several reports in the literature of deletions in or rearrangements involving 16p13.3, which is a highly gene-rich area (Brook-Carter et al 1994;Brown et al 2000;Eussen et al 2000;Horsley et al 2001).…”

Telomeres: a diagnosis at the end of the chromosomes

“…Her younger sister showed a more or less similar phenotype. Eussen et al 106 reported a boy with a submicroscopic deletion of 16p13.3-pter and duplication of 8q24.3-qter with tuberous sclerosis, adult polycystic kidney disease, and hypomelanosis of Ito. Brown et al 107 reported a newborn with cranial tubers and subcortical renal cysts suggestive of tuberous sclerosis and additional atypical features such as bilateral nasal colobomas of the eyes, inguinal hernias, glandular hypospadias, cryptorchidism, and facial dysmorphism (telecanthus, short palpebral fissures, broad nasal tip, small mouth with thin lips and small chin) caused by a der(16)t(16;19)(p13.3;p13.3).…”

Mutational analysis of the TSC1 and TSC2 genes in a diagnostic setting: genotype – phenotype correlations and comparison of diagnostic DNA techniques in Tuberous Sclerosis Complex

“…14,15 For DGGE, primers were designed using the Ingeny DGGE Primer Design program (primer sequences available upon request), and pooled PCR products were run on urea/formamide denaturing gradient polyacrylamide gels at 601C for 17 h (Ingeny phorU DGGE system). SSCP was performed on 50% of the patients and DGGE on 75% of the cohort.…”