ESPE Abstracts

Male, aged 6 years 3 months, recently moved from Peru, was admitted for suspected syndromic obesity. His medical history was unremarkable; no documented neonatal hypoglycemia or prolonged jaundice. Independent walking was achieved at 3 years and meaningful words at 2. Physical examination: height 99.2 cm (-3.57 SDS), -2.8 SDS below target height, BMI 27.43 kg/m2 (2.47 SDS); his weight has increased since the age of 4. Peculiar somatic characteristics were observed - saddle nose, chubby cheeks, stubby hands and feet; micropenis, bilateral cryptorchidism with hypoplastic scrotum; acanthosis nigricans. Laboratory tests: thyroxine and cortisol levels were normal; low dose ACTH test was adequate. Arginine test showed GH deficiency (peak 0.1 ng/ml). Fluid balance monitoring documented polyuria (approximately 3500 ml/day) and polydipsia (approximately 3500 ml/day) with normal electrolytes and plasma osmolality, and low urine osmolality. Partial central diabetes insipidus was confirmed through water deprivation test. Brain MRI showed aplastic anterior pituitary and ectopic posterior pituitary, consistent with congenital hypopituitarism. MRI also documented Chiari type I abnormality and a lipoma of the filum terminale located at L2-L4. Considering clinical, neuroradiological and laboratory data, oral desmopressin and GH replacement therapy were started. Genetic testing resulted as follows: karyotype 46XY; MS-MLPA for Prader Willi syndrome: negative; array CGH: microdeletion at chromosome 18 (18q23 of 28 oligonucleotides) of uncertain significance; NGS: heterozygous variant in MSK1 + hemizygous variant in MID1 gene, of uncertain significance. Two years after the start of therapy, at age 8 yr 3 months, brilliant results were achieved: height increased to -1.9 SDS (-1.05 SDS below TH) and BMI decreased to 21.14 kg/m2 (1.39 SDS). Subcutaneous injection of recombinant human LH and FSH showed partial response, thus surgical correction of cryptorchidism was performed. So far, no other pituitary defects were found. Language and motor improvements were observed during follow-up. Congenital hypopituitarism can be diagnosed at birth if typical signs are recognized. Later in childhood, growth failure is the main presenting feature. The diagnosis occurs later in some patients because the hormonal deficiencies evolve over time. In low- and middle-income countries, later diagnosis of hypopituitarism may be more frequent. However, appropriate hormone replacement, even if delayed, can significantly improve children's somatic and psychomotor development. In our patient, a gradual development of combined pituitary hormone deficiency along with migration and poor socio-economic status might be the causes of the late diagnosis. An initial misdiagnosis of syndromic obesity was made due to his clinical features.