Familial Report of Duplication 9p Syndrome

Abstract

Duplication 9p syndrome is a clinically well described syndrome characterized by growth retardation, developmental delay, skeletal malformations and craniofacial anomalies. We report a family starting with a male infant born by c-section at 39 weeks gestation to a 38 yo G6 P 4-0-1-4. The pregnancy was remarkable for an abnormal MSAFP placing the pregnancy at a 1:17 risk for Down Syndrome. The parents refused amniocentesis after receiving genetic counseling. At 35 weeks gestation a fetal ultrasound demonstrated mild polyhydraminos, borderline hydrocephalus, and a unilateral right pyelectasis along with a proximal hydroureter. The patient had an unremarkable delivery at an outside institution with Apgars of 9 and 10. Birth weight was 4790g (>95%). Ten hours post delivery the patient began to develop significant lymphedema of the right lower extremity which is what brought him to our attention. On presentation the patient appeared with bitemporal narrowing, short palpebral fissures, and small deep set eyes. The right extremity showed significant edema involving the foot extending to the distal portion of the thigh. An x-ray of the extremity showed no fracture. A cat scan of the head demonstrated diffuse cerebral volume loss with a slightly promineni left ventricle when compared to the right. A small left subdural hygroma was also noted A cardiac echocardiogram and a renal ultrasound were both normal. Cytogenetic study on peripheral blood lymphocytes revealed additional material on 9p. A FISH paint for chromosome 9 indicated that the extra material was duplication of 9. The G-banding pattern suggested duplication of 9p13p22. Peripheral blood was obtained from both parents and an identical karyotype was found in the mother. The mother was noted to have similar phenotvpic features to the proband, namely short palpebral fissures and small deep set eyes. The mother reported having a learning disability as a child completing only a 9^th grade education. Further family history showed the mother to have three other children all with another partner ages 11, 16, and 19 years of age. All 3 half siblings to the proband are reported as “slow”. These siblings are currently being worked up cytogenetically. Since first described m 1970. more than 100 cases have been reported with a duplication involving various size segments of the 9p chromosome. Familial cases have been reported with much less frequency. The clinical features and cytogenetic findings as compared to previous reported cases will be presented.