Familial Pallister-Hall syndrome.

In their report of sibs with the Pallister-Hall syndrome, Thomas et al' make the points that choanal atresia may be a feature of this condition and that it may be caused by a dominant gene. We have recently encountered an infant in whom the findings lend support to both of these suggestions. Our patient, a female, was the first child born to a healthy 31 year old female and her healthy and unrelated 38 year old partner, both of whom had three healthy children from previous relationships. Birth weight was 3780 g at term. Active resuscitation was needed and during the first day of life she required both ventilator support and intravenous glucose because of hypoglycaemia. Examination showed an unusual facial appearance with a flat nasal bridge, short nose, and anteverted nares. Other findings included a small exomphalos and postaxial polydactyly involving the left hand in which the fourth metacarpal was severely hypoplastic. Cranial CT scan showed a large, non-enhancing suprasellar mass with a posterior cystic component (fig 1). The clinical impression of osseous bilateral choanal atresia was confirmed (fig 2). Abdominal ultrasound showed mild bilateral renal hypoplasia. Chromosomal examination showed a normal female karyotype. Subsequent investigation showed evidence of panhypopituitarism and appropriate hormonal and electrolyte supplementation was initiated. The child continued to be ventilator dependent until bilateral surgical correction of the choanal atresia was undertaken at 16 days, after which her respiratory condition improved considerably. However, she continued to be extremely ill with several episodes of bradycardia culminating in death at the age of 48 days. Permission for necropsy was withheld. The clinical features in this child are strongly suggestive of the Pallister-Hall syndrome, in which choanal atresia appears to be an uncommon but potentially very important finding. No abnormality was present in either parent. The advanced paternal age of38 years is consistent with a new dominant mutation. Taking into account the paucity of parental consanguinity in the published cases along with the findings in the father of the sibs described by Thomas et al,' we agree that it is premature to conclude that the PallisterHall syndrome shows autosomal recessive inheritance.