Familial cystic hygroma with normal karyotype

Dear Sir

It is now becoming increasingly clear that cystic hygroma can be familial, with an autosomal recessive mode of inheritance. We present the fourth reported case of familial cystic hygroma (Tricoire et al. 1993) (Medline search done between the years 1966 – 2005).

A 37-year-old Caucasian female, gravida 4 para 1 underwent termination of pregnancy at 11 weeks for a first trimester diagnosis of fetal cystic hygroma. Subsequent two pregnancies also required terminations at 13 and 11 weeks for the same condition. Karyotyping of all three fetuses was normal (46XX, 46XY, 46XX). Her medical history and family history were unremarkable and there was no parental consanguinity. Her first pregnancy resulted in the delivery of a normal female child. Pathologic examination of terminated fetuses was not carried out, as the couple did not consent.

Aneuploidy is the single most likely cause of prenatally diagnosed cystic hygroma. Turner's syndrome is the most common association but other trisomies (13, 18 and 21) have also been reported. The presence of a familial cystic hygroma syndrome has been suggested (Teague et al. 2000). Euploid familial cases have a better outcome than aneuploid familial cases. The recurrence rate of euploid cases is close to 25%.

Our case is unique in view of the fact that the pregnancies represent first trimester diagnoses. The lack of post-mortem examination on the fetuses poses doubt as to whether other anomalies could have been present (though anomaly scans were normal). Of interest is the fact that the first pregnancy was not affected.

We await further publication of similar cases till the true genetic inheritance of the condition is established.