Clinical Brief
Congenital Hypopituitarism Associated with Hyperammonemia Abhay Bhoyar and Andrew Short Birmingham Children's Hospital, Steelhouse Lane, Birmingham, UK
ABSTRACT Neonatal onset hypopituitarism is a life threatening but potentially treatable metabolic condition. However, in the majority of cases it can be fatal due to the metabolic disturbances. We report a newborn with profound symptomatic hypoglycemia and hyperammonemia who initially was thought to have an inborn error of metabolism (IEM). After an initial falsely reassuring magnetic resonance imaging (MRI) brain scan, further endocrine investigation eventually led to the correct diagnosis and treatment. [Indian J Pediatr 2009; 76 (3) : 327-328] E-mail:
[email protected] Key words: Hypoglycemia; Congenital hypopituatarism (CH); Hyperammonemia; Magnetic resonance imaging; Inborn error of metabolism
CASE REPORT A female infant was born to unrelated healthy parents by normal vaginal delivery, after an uncomplicated pregnancy, with a weight of 3.290 Kg at 40 weeks of gestation. She had no evidence of asphyxia. An older female sibling is healthy, and there is no relevant family history. At 8 hours of age a midwife on the neonatal unit found her cold and floppy, after a short period of resuscitation she was admitted to the neonatal unit for further management. Her true laboratory blood sugar was 0.3 mmol/L. After investigations for hypoglycemia she was treated with dextrose bolus and infusion. On examination the head circumference was 37.5cm (98th- 99.6th centile) with wide open fontanelles, weight was 3.290 Kg(25th- 50th centile) and length was 47 cm (2nd-9th centile). She had no cleft lip or palate. She was floppy but clinical examination was unremarkable.From initial screening investigations, the ammonia level was 512 µ mol/ l, raising concerns about possible inborn error of metabolism (IEM). She was kept Nil by Mouth, on a dextrose infusion to maintain blood sugar above 2.5 mmol/l. The remaining blood analysis on day-1 of life was as follows: Total bilirubin 304 u mol/L, conjugated bilirubin 12 u mol/L, ALT 129 u/ L, GGT 295u/L.The chromosomal analysis revealed a normal female karyotype (46, XX). MRI of the brain was Correspondence and Reprint requests : Dr Abhay Bhoyar Research Fellow, Pulse ox study Cardiology Department, Birmingham Children's Hospital, Steelhouse Lane, Birmingham B4 6NH, UK. Tel: 01213339999, Fax: 01213339401 [DOI–10.1007/s12098–009–0001–9] [Received September 12, 2007; Accepted May 07, 2008]
Indian Journal of Pediatrics, Volume 76—March, 2009
Fig. 1. MRI, T1-weighted midline sagittal image showing pituitary hypoplasia and an ectopic posterior pituitary in tuber cenereum of hypothalamus.
reported normal but ophthalmology review showed optic hypoplasia. The serum ammonia gradually fell and further investigations showed no evidence of a metabolic disorder. On day-7 of life she had a further episode of profound hypoglycemia associated with extravasation of the intravenous infusion, when the diagnosis became apparent from the following endocrine investigations: cortisol
