engleski

Terminal trisomy 7p secondary to maternal 7p22 ; 8p23 translocation

Partial duplications of the short arm of chromosome 7 have been described in 60 cases. The size of duplicated 7p segment is variable and frequent breakpoints are in 7p15 and 7p21. Smaller terminal duplications are, however, rare and reported in three patients so far. Here we report a patient with partial trisomy 7p resulting from malsegregation of maternal balanced translocation. Our patient is the first child of healthy nonconsanguineous parents. Her younger brother, born after two spontaneous abortions, is normal. The proposita was first evaluated at the age of 6 months because of craniofacial dysmorphism. Clinical examination showed dolichocephaly, high large forehead, ocular hypertelorism, epicantic folds, narrow palpebral fissures, depressed nasal bridge, anteverted nares, low set and malformed ears, micrognatia, retrognatia, high arched palate, hypotonia, developmental delay and ventriculomegaly. Cytogenetic analysis was performed on slides obtained by standard peripheral blood cultures and stained by GTG-, RBG- and CBG- banding methods. The analysis revealed normal karyotype. Subsequent screening of subtelomeric regions by FISH and multi-colour probe panel ToTelVysion (Vysis) revealed unbalanced rearrangement of short arms of chromosomes 7 and 8. The detected abnormality was verified by FISH using chromosome specific subtelomeric and whole chromosome painting probes (Vysis). Paternal karyotype was normal, while the mother and the brother have balance translocations with the breakpoints at 7p22 and 8p23. The infant’ s karyotype was interpreted as 46, XX, der(8)t(7 ; 8)(p22 ; p23)mat. The child has a duplication of 7p22→ pter, and a deletion of 8p23→ pter. This report contributes to the delineation of clinical features of duplication 7p22→ pter.

trisomy 7p; translocation 7/8; developmental delay

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