Prenatal diagnosis and counseling of Emanuel syndrome: Two case reports.

OBJECTIVE

Emanuel syndrome is a rare inherited chromosomal disorder characterized by the presence of a derivative chromosome 22 resulting from a translocation between chromosomes 11 and 22. Since the number of reported cases in Asian is still small, we mean to present 2 more cases diagnosed prenatally and review similar case reports to better understand the syndrome when abnormal findings were found prenatally.

CASE REPORT: Two cases of Emanual syndrome were found where one draws attention due to abnormal serum marker and thickened nuchal translucency, and the other was found when prenatal ultrasonography detected multiple anomalies. Genetic amniocentesis revealed 47 chromosomes gaining an additional marker chromosome arising from malsegregation in a balanced translocation heterozygote with 46, XX, t(11;22) (q23.3;q11.2).

CONCLUSION

While different anomalies were found, both of our cases along with others presented 3:1 segregation with tertiary trisomy resulting in Emanual syndrome. Chromosome of the quadrivalent is small in content ("lop-sided" quadrivalent) at meiosis I, which tends to separate in a 3:1 segregation fashion.