Proximal 5p trisomy resulting from a marker chromosome implicates band 5p13 in 5p trisomy syndrome

Abstract

We describe an infant with trisomy of (5)(p10p13.1) resulting from a de novo marker chromosome. The marker's origin was identified by chromosome microdissection and reverse in situ hybridization. The clinical findings are compared to those of other partial and complete 5p duplications. This case further defines the critical region of 5p trisomy syndrome to proximal 5p.

Partial 5p monosomy or trisomy in 11 patients from a family with a t(5;15)(p13.3;p12) translocation

“…The segment that is deleted in 5p monosomy patients involves the critical region for the syndrome at 5p15.2 to 5p15.3 (Niebuhr 1978;Overhauser et al 1986Overhauser et al , 1994. On the other hand, the duplicated segment of 5p does not involve the critical region of the 5p trisomy syndrome, mapped to 5p10-5p13.1 (Lorda-Sanchez et al 1997;Avansino et al 1999;D'Amato Sizonenko et al 2002). The patients with monosomy 5p of the family described here presented the main features of the cri-du-chat syndrome: cat-like cry, microcephaly, severe mental retardation, depressed nasal bridge, hypertelorism, epicanthic folds, downward slanted palpebral Wssures, and muscular hypotonia.…”

“…The 5p trisomy phenotype is quite variable, although a critical region responsible for the main malformations of this syndrome was mapped to 5p10-5p13.1, a region that is not present in our patients with 5p duplication. Literature shows that the critical region 5p11-5p13.1 accounts for the main malformations of the 5p trisomy syndrome, such as macrodolicocephaly, craniofacial anomalies, hypotonia, mental retardation, and cardiac, renal, central nervous system and intestinal anomalies (Vowles et al 1984;Avansino et al 1999;D'Amato Sizonenko et al 2002). As our patients presented moderate mental retardation, hypotonia and macrodolicocephaly, bulbous nose, long philtrum, high-arched palate, macroglossia and microretrognathia, the region 5p13.3 is probably involved in these features.…”

“…The most frequent 5p duplications involve 5pter to 5p13 and result in variable clinical features including mental retardation, dolicocephaly, prominent occiput, round face, downward slating palpebral Wssures, strabismus, low-set ears, short and bulbous nose, long philtrum, high-arched palate, macroglossia and small jaw (Brimblecombe et al 1977;Zabel et al 1978;Vowles et al 1984). Partial 5p trisomy is usually due to partial duplications inherited from translocation or inversion carriers and, less frequently, due to insertions or marker chromosomes (Lorda-Sanchez et al 1997;Avansino et al 1999). The patients may show duplications distal to 5p13.3 (Chia et al 1987;Webb et al 1988;Zenger-Hain et al 1993), complete 5p duplication (Reichenbach et al 1999;Velagaleti et al 2000;Grosso et al 2002), and duplication of the 5p proximal region encompassing 5p10 to 5p13 (Lorda-Sanchez et al 1997;Avansino et al 1999;D'Amato Sizonenko et al 2002).…”

“…Partial 5p trisomy is usually due to partial duplications inherited from translocation or inversion carriers and, less frequently, due to insertions or marker chromosomes (Lorda-Sanchez et al 1997;Avansino et al 1999). The patients may show duplications distal to 5p13.3 (Chia et al 1987;Webb et al 1988;Zenger-Hain et al 1993), complete 5p duplication (Reichenbach et al 1999;Velagaleti et al 2000;Grosso et al 2002), and duplication of the 5p proximal region encompassing 5p10 to 5p13 (Lorda-Sanchez et al 1997;Avansino et al 1999;D'Amato Sizonenko et al 2002). Literature shows that patients with duplications distal to 5p13.3 (Baialardo et al 2003;Cervera et al 2005) present a relatively milder phenotype compared to complete 5p duplications (Reichenbach et al 1999;Velagaleti et al 2000;Grosso et al 2002) and to duplications of the proximal regions 5p11-5p13.2, suggesting a critical region between 5p10 and 5p13.1 (Lorda-Sanchez et al 1997;Avansino et al 1999;D'Amato Sizonenko et al 2002).…”

Chromosome 5 derived small supernumerary marker: towards a genotype/phenotype correlation of proximal chromosome 5 imbalances

“…3). A critical region has been proposed for 5p13, which, in trisomy, is associated with pregnancy complicated by polyhydramnions, psychomotor delay, and characteristic facial features (Avansino et al 1999;D'Amato Sizonenko et al 2002). sSMC(5) involving euchromatin in the q-arm are more rare and a genotype/phenotype correlation is difficult to ascertain due to the heterogeneity of the size and content of the sSMC.…”