A case of de novo complex chromosomal abnormality involving a t(8;10) and an interstitial deletion 5q(q33.1-q34) characterized by GTG banding, FISH and cCGH

Abstract

Interstitial deletions of the long arm of chromosome 5 involving the region 5q33.1-q34 are rare occurrences. The clinical features of patients carrying similar deletions include dysmorphic facial features, such as epicanthus, retrognatia, protruding left ear and asymmetric mouth, high-arched palate, four inger lines and clinodactyly of digits II and V on both hands. We report on a female child aged 13 presenting with development delay, agenesis of the corpus callosum, hallux diverted into, clinodactyly of 3rd, 4th and 5th ingers, obesity, hepatic steatosis, vesicular lithyasis and bilateral macular changes. Classical karyotyping using high resolution GTG banding revealed a de novo complex rearrangement including three abnormal chromosomes: 5, 8 and 10; apparently there was an inversion in the long arm of chromosome 5 and a t(8;10). FISH whole chromosome painting probes confirmed an apparently balanced t(8;10), a deleted chromosome 5 and confirmed the inexistence of any other chromosomal involvement. To define the deletion breakpoints and the extent of the deletion, cCGH techniques were performed and revealed an interstitial deletion 5(q33.1"q34). The final karyotype was: 46,XX,der(5)inv(5)(q21q33.1)del(5)(q33.1q34)t(8;10)(q13;q21.2)dn. ish cgh del(5)(q33.1q34). The authors enhance the importance of using high resolution banding combined with molecular cytogenetic techniques for more precise definition of complex chromosomal rearrangements in patients with uncharacteristic phenotypic features and compare the present case findings with previously published data.