Molecular cytogenetic analysis and clinical findings in a newborn with prenatally diagnosed rec(7)dup(7q)inv(7)(p22q31.3)pat

Abstract

We report prenatal and early postnatal findings in a newborn with a partial trisomy of chromosome 7 (7q31.3-qter), arising from meiotic recombination of a paternal pericentric inversion, inv(7)(p22q31.3). The inversion breakpoints were localized and the regions of duplication and deletion were defined by fluorescence in situ hybridization (FISH) analysis using a series of locus-specific and subtelomeric probes. To our knowledge, only three cases involving a recombinant 7 with duplication of 7q have been reported, two of these being first cousins. The clinical findings in our patient included skeletal abnormalities, facial dysmorphism, dilated cerebral ventricles, microretrognathia and short neck. These findings and some aspects of the neonatal course were consistent with the phenotype previously reported for duplication of distal 7q, without associated monosomy for sequences from another chromosome.

Small inherited terminal duplication of 7q with hydrocephalus, cleft palate, joint contractures, and severe hypotonia

“…Contractures, club feet, limited joint movements and clinodactyly at birth have been described in patients with partial trisomy 7q irrespective of the size of the duplication (Forabosco et al, 1988;Goodman et al, 1999;Romain et al, 1990;Speleman et al, 2000;). A subset of these patients also showed severe hydrocephalus (Forabosco et al, 1988;Bartsch et al, 1990;Stratton et al, 1993;Speleman et al, 2000).…”

“…Patients with larger duplications present with visceral defects, cranio-facial malformations and mental retardation (Courtens et al, 2001). More terminal duplications are associated with similar facial characteristics and severe developmental delay (Bartsch et al, 1990;Goodman et al, 1999). No definite genotype-phenotype correlation has been established so far (Forabosco et al, 1988;Romain et al, 1990;Hoo et al, 1995).…”

Isolated trisomy 7q21.2-31.31 resulting from a complex familial rearrangement involving chromosomes 7, 9 and 10

“…There are many publications on partial trisomies in 7q. In most cases the duplication resulted from a familial translocation involving the long arm of chromosome 7 and another chromosome leading to partial trisomy/monosomy 7 and partial trisomy/monosomy of the translocation partner, respectively [ 3 - 9 ]. About 19 patients with isolated trisomy 7 involving various regions of 7q have been described [ 10 , 11 ].…”

Prenatal diagnosis of a partial trisomy 7q in two fetuses with bilateral ventriculomegaly

“…Fourteen out of 54 cases have pure trisomy, 6 out of 54 associated monosomy involving acrocentric short arms and 34/54 associated monosomy involving other chromosomes (Berger et al, 1974;Turleau et al, 1976;Schinzel and Tonz, 1979;Yunis et al, 1980;Novales et al, 1982;Forabosco et al, 1988;Bartsch et al, 1990;Goodman et al, 1999). Fourteen out of 54 cases have pure trisomy, 6 out of 54 associated monosomy involving acrocentric short arms and 34/54 associated monosomy involving other chromosomes (Berger et al, 1974;Turleau et al, 1976;Schinzel and Tonz, 1979;Yunis et al, 1980;Novales et al, 1982;Forabosco et al, 1988;Bartsch et al, 1990;Goodman et al, 1999).…”