Perinatal diagnosis of a fetus with an unbalanced translocation 46,XY,der(10)t(6;10)(p22;q26.1) with multiple malformations:a case report and literature review

Abstract

The phenotype of an unbalanced translocation is characterized by the dosage effects of the affected genes in the translocated chromosome. We present the case of a fetus with a paternally derived unbalanced 46,XY,der(10)t(6;10)(p22;q26.1) translocation, detected following growth retardation and cardiac malformation. In trisomy 6p and 10q26 monosomy, external surface malformations, including characteristic facial abnormalities, and neurological or higher effects have been reported. Developmental delay and hypotonia are reported in ≤ 80% of cases of 10q monosomy. Herein, low birth weight, cephalic abnormalities including microcephaly, low-set ears and a high arched palate, ambiguous genitalia including scrotal hypoplasia and cryptorchidism, and congenital heart defects, including ventricular septal defect and pulmonary atresia, were observed. Neurological impact was not evaluated due to neonatal death. The mortality rate and frequency of low birth weight in such translocations has been seldom reported. In this case, severe cardiac malformation and low birth weight may have caused early neonatal death. Whilst Trisomy 6 is associated with low birth weight and perinatal death, few studies have reported these outcomes in 10q26 deletion syndrome. Our findings therefore contribute to the evidence base regarding unbalanced translocations and may improve the clinical management of such patients.

Keywords: congenital heart disease; multiple malformations; perinatal diagnosis; severe fetal growth restriction; unbalanced translocation.

Figure 1.

Karyotype analysis of amniotic fluid cells. Chromosome abnormalities are indicated by arrows. An additional chromosomal region was identified in chromosome 10.

Figure 2.

G-banding for the karyotype of the father revealed a balanced 46,XY,t(6;10)(p22;q26.1) translocation. The arrow indicates the breakpoint of chromosome 6 and chromosome 10.