Derivative chromosomal structures from a ring chromosome 4

Summary This report describes the results from cultured lymphocytes studied at metaphase, anaphase, and interphase from an individual with a ring chromosome 4. A ring was present in 90.1% of metaphases. Special attention was directed towards the occurrence of derivative chromosomal structures, such as partially duplicated and triplicated rings, tricentric rings, chains of 3 interlocked rings, rod-shaped chromosomes, pulverized rings, and others.The clinical features of the individual (small stature and impaired mental development, hypoplastic thumbs, ptosis palpebrae hypoplastic external male genitalia, abnormal dermatoglyphic pattern) did not conform to a specific phenotype.

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Zusammenfassung Die Lymphocyten eines Patienten mit Ringchromosom 4 wurden in der Meta-, Ana-und Interphase beobachtet. 90,1% der Metaphasen wiesen einen Ring auf. Besondere Aufmerksamkeit wurde abnormen, aus dem Ring entstandenen Chromosomen zugewandt. Es fanden sich u. a.: partielle Doppel-und Dreifachringe, Ringe mit 3 Zentromeren, Ringe aus 3 miteinander verketteten Ringen, stabförmige Chromosomen und pulverisierte Ringe.Die Symptome des Patienten (Minderwuchs, Schwachsinn, Hypoplasie der Daumen, Ptosis palpebrae, Hypoplasie des äußeren genitale, abnorme Dermatoglyphen) waren zum größten Teil unspezifish.

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This work was supported in part by grants from the Deutsche Forschungsgemeinschaft and is part of a thesis by R.N. for a medical doctorate.