Balanced complex chromosome rearrangement ascertained through prenatal diagnosis

✍ Scribed by Farrell, S. A. ;Summers, A. M. ;Gardner, H. A. ;Uchida, Irene A.

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 177 KB
• Volume: 52
• Category: Article
• ISSN: 0148-7299
• DOI: 10.1002/ajmg.1320520322

✦ Synopsis

Letter to the Editor

Balanced Complex Chromosome Rearrangement Ascertained Through Prenatal Diagnosis l b the Editor:

We are reporting on a family with a balanced complex chromosome rearrangement (BCCR) ascertained on the basis of a chromosome abnormality detected a t prenatal diagnosis. Amniocentesis for late maternal age in a woman's first pregnancy documented a female fetus with a n unbalanced karyotype. There was a n extra interstitial segment in the long arm of chromosome 21 (21qS). The mother was found to have the following BCCR: der(7)t(7;10)(q21.13;q23.33)ins(21;7)(q21.3; q11.22q21.131, der(lO)t(7;1O)(q21.13;q23.33), der( 21) ins(21;7)(q21.3;qll.22q21.13). The fetal karyotype then was interpreted as trisomic for the region 7q11.22+ q21. 13 [i.e., 21q+]. After counselling the couple decided to terminate the pregnancy. At autopsy, the only anomalies noted were a prominent mandible and apparently low-set and posteriorly angulated ears.

In another centre, the sister of the above woman (Fig. 1) was found to carry the same BCCR. At amniocentesis, her male fetus had an unbalanced rearrangement that differed from the karyotype of the sister's fetus. It was monosomic for 7q11.22+q21.1 [i.e., 7q-I. This pregnancy was terminated. Autopsy showed apparently low-set ears and a n absent left kidney. Radiographs demonstrated lumbar scoliosis secondary to abnormal lumbar vertebrae. This woman's normal son also carried the BCCR.

The mother of these two women carried the BCCR. She lost a female infant with a "hole in the heart" and had one normal son, in addition to the daughters described here. One of her brothers was significantly mentally handicapped. Her other three sibs were normal.

To our surprise, the BCCR identified in this kindred was identical to that of Wang et al. [19931. When further relatives came for counselling, it was discovered that the mother described by Wang et al. [1993] was a second cousin to the sisters reported here (Fig. 1, W-4).