Interstitial deletion of 2(q33q36) in a child with congenital abnormalities

Deletion 2q36.2q36.3 with multiple renal cysts and severe mental retardation

Interstitial 2q36 deletion is a rare event. We report on a patient with a de novo del(2)(q36.2q36.3) interstitial deletion of the long arm of chromosome 2 diagnosed by classical banding. The phenotype comprised facial dysmorphism, enlarged kidneys with multiple renal cysts, abnormal minora labia, asymmetric lower limbs with dysplastic patella, and severe mental retardation. By physical mapping, using array-comparative genomic hybridisation (CGH) confirmed by Fluorescent In Situ Hybridisation (FISH), the breakpoints of the deletion were mapped and the size of the deletions was measured: 5.61+/-0.19Mb. A skin biopsy was analysed using electronic microscopy showing an alteration of the structure and organisation of the dermal and peri-neuronal basement membrane. The relation between the phenotype and the deletion of both COL4A4 and COL4A3 genes, located in 2q36.3 loci, as well as the disruption of TRIP12 were discussed.

Deletion of chromosome 2q24-q31 causes characteristic digital anomalies: case report and review

We describe a newborn boy with multiple anomalies, including bilateral split foot and an interstitial deletion of chromosome 2 (q24.2-q31.1). Four additional cases in 2 families involving similar deletions have been reported. Bilateral digital anomalies of hands and feet were seen in all 5 cases, including a wide cleft between the first and second toes, wide halluces, brachysyndactyly of the toes, and camptodactyly of the fingers. Other common manifestations have included postnatal growth and mental retardation, microcephaly, down-slanting palpebral fissures, micrognathia, and apparently low-set ears. Bilateral digital anomalies were reported in 22 of 24 cases with deletions including at least part of region 2q24-q31. Digital anomalies were not prevalent in 18 patients with deletions of chromosome 2q not overlapping 2q24-q31. 2q31.1 appears to be the common deleted segment in all cases with significant digital anomalies, which implies the existence of one or more genes involved in distal limb morphogenesis in this region. HOXD13 and EVX2, located in the proximity of 2q31, were not deleted in our patient by Southern analysis. Bilateral digital malformations of the hands and feet associated with other anomalies should be evaluated by chromosome analysis focused at the 2q24-q31 region.

De novo inv(2)(p21q31) associated with isolated bilateral microphthalmia and cataracts

We report on a patient with bilateral microphthalmia and unusual cataracts with a de novo pericentric inversion of chromosome (2)(p21q31). A literature review of previous associations of eye abnormalities and anomalies of chromosome 2 suggests probable gene locations for eye development.

Interstitial deletion del(2)(q24q31) with a phenotype similar to del(2)(q31q33)

A 3 3/12-year-old girl with multiple anomalies is reported. An interstitial deletion del(2)(q24q31) was demonstrated. There is considerable overlap of symptoms in cases with del(2)(q31q33), which are reviewed.

Deletions in chromosome 2 and fragile sites

We report on 2 patients with de novo deletions of 2q and chromosome constitutions of 46,XY,del(2)(q32.3q33.3) and 46,XX,del(2) (q21q23.2), respectively. Comparisons of breakpoints of interstitial deletions show frequent correspondence to common fragile sites.