Sporadic problem. After reviewing the federal nih directory of rare disorders & other resources it is evident no new data has surfaced on this problem. Lymphangioma aka cystic hygroma is a sporatic defect with no defined genetic influence.
Rare. Happens in about 5000-7500 live births. Most common site is the head and neck area. Can be picked up prenatal ultrasound as a cystic neck mass.
No. Usually it is an isolated event.