Partial trisomy 1q syndrome

Abstract

Six cases of partial trisomy lq, including four cases from the literature and our own two observations are summarized with respect to their clinical symptoms. Distinct similarities of the external aspect and of internal malformations allow the delineation of a syndrome of partial trisomy lq.

Partial trisomy 1q due to tandem duplication

“…Tandem duplication lq32 -+ lq44, lead-ing to partial trisomy Iq has been described previously by Steffensen et al (1977). In their case, as in ours, the clinical features are solely due to the l q triplication and are not influenced by accompanying monosomy, as might be the case in partial trisomy l q due to unbalanced translocation (Rehder & Friedrich 1979).…”

“…Sirs, Rehder & Friedrich (1979) recently described partial trisomy l q syndrome and summarized the characteristic symptoms. These observations may be supplemented by the case of a boy (now aged 9 months) in whom similar clinical features enabled us to identify a de novo elongation of the long arm of chromosome 1 as tandem duplication.…”

Partial trisomy 1 (q42→ter)

“…She was trisomic for about one-third of the terminal long arm of chromosome l(lq3-lq44). The half-brothers described by Taysi & Sekhon (1978), the case of Bonfante et al (1978) and the male child and female fetus of the family described by Rehder & Friedrich (1979) were all trisomic for the segment 1q32-44 (translocated to differenlt chromosomes, though). Their clinical findings differed markedly, with the half-brothers being relatively mildly dysmorphic, mentally retarded adults and other patients presenting with more severe clinical findings and early death.…”

“…Only a few cases of partial trisomy of the long arm of chromosome 1 have been reported in the literature. Duplication of the major part of the long arm of chromosome 1, distal to the band lq23 or 24, has been reported in six separate cases with different amounts of extra chromosome 1 material (Van der Berghe et al 1973, Neu & Gardner 1973, Norwood & Hoehn 1974, Bonfante et al 1978, Taysi & Sekhon 1978, Rehder & Friedrich 1979. The patients have presented with a rather divergent pattern of birth defects and dysmorphic features.…”