Prenatal diagnosis and molecular cytogenetic characterization of mosaicism for r(10) and monosomy 10 at amniocentesis in a fetus associated with perinatal growth restriction but no gross structural abnormalities.

OBJECTIVE

We present prenatal diagnosis and molecular cytogenetic characterization of mosaicism for r(10) and monosomy 10 at amniocentesis in a fetus with a 10p15.3 microdeletion and a 10q26.3 microdeletion.

CASE REPORT: A 37-year-old, gravida 2, para 1, woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 45,XX, -10[11]/46,XX,r(10)[6]. Prenatal ultrasound was normal. She was referred for genetic counseling, and repeat amniocentesis at 21 weeks of gestation revealed a karyotype of 46,XX,r(10)[15]/45,XX,-10[5]. The parental karyotypes were normal. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed a 2.182-Mb 10p15.3 deletion encompassing the genes of ZMYND11 and DIP2C, and a 2.257-Mb 10q26.3 deletion outside the genes of DOCK1 and EBF3. Prenatal ultrasound showed intrauterine growth restriction but no gross structural abnormalities. The parents elected to continue the pregnancy, and a 2425-g baby was delivered at 40 weeks of gestation without craniofacial dysmorphism. The cord blood had a karyotype of 46,XX,r(10)[29]/45,XX,-10[9]/47,XX,r(10),+r(10)[1]/46,XX[1]. When follow-up at age four months, the peripheral blood had a karyotype of 46,XX,r(10) [32]/45,XX,-10[8], her body weight was 5.1 Kg (<3 centile), and body height was 58 cm (<3 centile). She did not have craniofacial dysmorphism. When follow-up at age one year and two months, her body weight was 5.9 Kg (<3 centile), and body height was 68.5 cm (<3 centile). She manifested motor and speech developmental delay but no hypotonia. Brain computed tomography and whole-body ultrasound examination showed no abnormalities.

CONCLUSION

Mosaicism for r(10) and monosomy 10 at prenatal diagnosis can be associated with perinatal growth restriction but no gross structural abnormalities.