J Genet Med.  2009 Dec;6(2):175-178.

Prenatal Diagnosis of the 22q11.2 Duplication Syndrome

• Lee MH
• Park SY
• Lee BY
• Choi EY
• Kim JW
• Park JY
• Lee YW
• Oh AR
• Lee SY
• Yang JH
• Ryu HM

Abstract

The 22q11.2 duplication syndrome is an extremely variable disorder with a phenotype ranging from normal to congenital defects and learning disabilities. Recently, the detection rate of 22q11.2 duplication has been increased by molecular techniques, such as array CGH. In this study, we report a familial case of 22q11.2 duplication detected prenatally. Her first pregnancy was terminated because of 22q11.2 duplication detected incidentally by BAC array CGH. The case was referred due to second pregnancy with same 22q11.2 duplication. We perfomed repeat amniocentesis for karyotype and FISH analysis. Karyotype analysis from amniocytes and parental lymphocytes were normal, while FISH analysis of interphase cells presented a duplication of 22q11.2 in the fetus and phenotypically normal mother. The fetal ultrasound showed grossly normal finding. After genetic counseling about variable phenotype with intrafamilial variability with 50% recurrence rate, the couple decided to continue the pregnancy. The newborn had no apparent congenital abnormalities until 2 weeks after birth. We recommend that family members of patients with a 22q11.2 duplication be tested by the interphase FISH analysis. Also, we point out the importance of genetic counseling and an evaluation of the clinical relevance of diagnostic test results.

Keyword

22q11.2 duplication; Prenatal diagnosis; FISH

MeSH Terms

Amniocentesis
Congenital Abnormalities
Diagnostic Tests, Routine
Fetus
Genetic Counseling
Humans
Infant, Newborn
Interphase
Karyotype
Learning Disorders
Lymphocytes
Mothers
Parents
Phenotype
Pregnancy
Prenatal Diagnosis
Recurrence