Abstract 78: Pituitary stalk interruption syndrome (PSIS) is rare disease

Background: Pituitary stalk interruption syndrome (PSIS) is rare disease characterized by breech, hypoglycemia, micropenis/cryptorchidism at birth, short stature in childhood and later with delayed puberty. Aims: Single centre study to characterize- the clinical, biochemical and radiological features, treatment and follow up of PSIS patients; phenotypic difference in patients with PSIS-Isolated GHD (IGHD) and PSIS-combined pituitary hormone deficiency (CPHD) by comparing with GHRHR, and POU1F1, PROP1 (combined) mutated cases respectively. Result: Of 56 PSIS (all sporadic; males-80%) cases, 36 were CPHD. Most common presentation was short stature (64.3%). Overall PSIS has higher breech presentation (36% vs. 6%) on comparing with genetically positive cases of IGHD/CPHD. Neonatal hypoglycemia was more frequent in CPHD (22% in both PSIS-CPHD and genetically positive CPHD) as compared to IGHD (0%:PSIS-IGHD and 1.9%:GHRHR-IGHD). Similarly, neonatal jaundice was more common in CPHD (42%:PSIS-CPHD and 22.2%:genetically positive CPHD) as compared to IGHD (5% in PSIS-IGHD and 1.9%:GHRHR-IGHD). Extra-pituitary malformation and skeletal anomalies were exclusively seen in PSIS cohort (CPHD>IGHD). Absent pituitary stalk and hyperprolactinemia was more frequent in PSIS-CPHD than PSIS-IGHD cohort. 75% IGHD and 83% CPHD males failed to achieve spontaneous puberty on follow up. Conclusion: Late presentation with short stature and delayed puberty is common. Breech presentation was higher in PSIS than other mutation positive cases. Radiological and skeletal abnormalities were only seen in PSIS cohort.