Familial complex chromosomal rearrangement resulting in duplication/deletion of 6q1c to 6q16

Abstract

A familial complex chromosomal rearrangement (CCR) was ascertained through a mentally retarded, dysmorphic individual. Carriers of the CCR have the karyotype 46,XX or XY, t(6;15)(q16;q21), ins(3;6)(q12;q14q16), and malsegregation of the CCR resulted in loss of the segment 6q14 to 6q16 in the proband, and in an additional copy of the same segment in three members of the extended family. The proband has features similar to other reported cases with deletion of 6q1. The individuals with duplication of 6q14 to 6q16 have moderate mental retardation, short stature, obesity, microcephaly, brachycephaly, a short smooth philtrum, central hair whorl, simian creases, 5th finger brachydactyly and skeletal disproportion. In the 4-generation family, CCR carriers have a 20% empiric risk of phenotypically abnormal livebirths.

New insights into the phenotypes of 6q deletions

“…However, in 4 cases hypotonia progressed to hypertonia [Rivas et al, 1986;Schwartz et al, 1984;Stevens et al, 1988]. Four patients were hypertonic at the time of the first reported evaluation [Cote et al, 1981;Narahara et al, 1991;Roland et al, 1993;Stevens et al, 1988]. No mention of tone was made in 21 of the 57 cases.…”

“…We reviewed 12 cases (including case 1) with proximal deletions of 6q [DiLernia and Albertini, 1994;Gershoni-baruch et al, 1996;Lonardo et al, 1988;McNeal et al, 1977;Roland et al, 1993;Romie et al, 1996;Rose et al, 1992;Slater et al, 1987;Turleau et al, 1988;Valtat et al, 1992;Yamamoto et al, 1986;Young et al, 1985]; 86% had upslanting palpebral fissures. This finding was also present in 23% of more distal deletions of 6q.…”

“…Despite 57 case reports of deletions of the long arm of chromosome 6, there is little indication in the literature of phenotypic correlations with deletions of specific regions of chromosome 6q [Bartoshesky et al, 1978;Bzdú ch and Lukáčová , 1989;Chery et al, 1989;Cote et al, 1981;Dallapiccola et al, 1978;DiLernia and Albertini, 1994;Fryns et al, 1986Fryns et al, , 1991 Gershonibaruch et al, 1996;Glover et al, 1988;Goldberg et al, 1980;Hagameijer et al, 1977;Horigome et al, 1991;Ito et al, 1989;Kassikoff and Sekhon, 1990;Kueppers et al, 1977;Liberfarb et al, 1978;Lonardo et al, 1988;Matkins et al, 1985;McLeod et al, 1990;McNeal et al, 1977;Meng et al, 1992;Mikkelsen et al, 1973;Milošević and Kaličanin, 1975;Nakagome et al, 1980;Narahara et al, 1991;Oliveira-Duarte et al, 1990;Pandya et al, 1995;Park et al, 1988;Rivas et al, 1986;Roland et al, 1993;Romie et al, 1996;Rose et al, 1992;Scarsbrough et al, 1984;Schwartz et al, 1984; ShenSchwartz et al, 1989; Schnizel, 1984; Slate et al, 1987;Stevens et al, 1988;Tajara et al, 1990;Tranebjaerg et al, 1986;Turleau et al, 1988;…”

A distinctive phenotype associated with an interstitial deletion 6q14 contained within a de novo pericentric inversion 6 (p11.2q15)

“…High cheek bones and a broad, flat nasal bridge were described by Roland et al (1993) in a patient 24 years of age with a deletion 6q14 to 6q16. No consistent pattern emerges when one compares the previous reports of deletions involving the regions between 6q11 and 6q16 (Table 1 and Fig.…”

“…Interstitial deletions of the proximal long arm of human chromosome 6 between 6q11 and 6q16 appear to be uncommon. Only 15 patients with deletions in this region have been recorded (McNeal et al, 1977;Young et al, 1985;Cerrillo et al, 1985;Yamamoto et al, 1986;Lonardo et al, 1988;Turleau et al, 1988;Slater et al, 1988;Valtat et al, 1992, two patients; Rose et al, 1992;Roland et al, 1993;GershoniBaruch et al, 1996;Romie et al, 1996;Kumar et al, 1997;Hopkin et al, 1997). Except for the patients described by Gershoni- Baruch et al (1996), Kumar et al (1997), and Hopkin et al (1997), the deletions in these patients involve different regions between 6q11 and 6q16.…”