Revaluation twenty-three years later of a supernumerary derivative chromosome 9
✍ Scribed by Yardin, Catherine ;Esclaire, Fran�oise ;Terro, Faraj ;Barthe, Dominique ;Gilbert, Brigitte
- Publisher
- John Wiley and Sons
- Year
- 2002
- Tongue
- English
- Weight
- 87 KB
- Volume
- 111
- Category
- Article
- ISSN
- 0148-7299
No coin nor oath required. For personal study only.
✦ Synopsis
We wish to report the case of A.B., whose abnormal karyotype was performed twice, the second time after an interval of 23 years; the second investigation benefited from improved techniques, especially the use of fluorescence in situ hybridization (FISH).
After an uneventful pregnancy, the propositus was born at term by cesarean in October 1977 from nonconsanguineous healthy parents. Her older brother was normal. Important hypotonia was noted at birth. Physical examination showed pectus excavatum, bilateral hip subluxation and bilateral single palmar crease. Her karyotype was performed (R-banding) and showed a surpernumerary incomplete derivative chromosome 9 in all the examined cells. It seemed that the derivative chromosome 9 lacked a part of chromosome 9 long arms (Fig. 1a). Both parents had normal karyotypes. There was no evident problem concerning the paternity.
Twenty-three years later, in 2000, the brother wished to have a child but was worried about his sister's chromosome abnormality. A.B. had, indeed, severe mental retardation: she started walking at five years and could not speak at all. Her puberty was delayed, at 18 years. At 23 years, she had a normal stature and dysmorphic features: hypotelorism, downslanting palpebral fissures, prominent nose, and prognathism. No speech was possible, but she could understand some words. She felt very nervous when placed in a new situation.
Another chromosomal analysis was therefore performed on her. The supernumerary derivative chromosome 9 was found again in all the examined cells (Fig. 1b). Incomplete hybridization of this supernumerary chromosome was obtained by FISH using a whole chromosome 9 painting (WCP9; Vysis) (Fig. 2a). Multi-FISH (multiprobe octochrome; Cytocell) was then performed, and showed that the remainder of derivative