Hypophosphatemic osteomalacia is a rare form of metabolic bone disorder in neurofibromatosis type 1 (NF1). The exact disease mechanism of this disorder in NF1 is yet to be established. We present a 44-year-old female known to have NF1, who presents with debilitating bone pain, weakness and multiple fractures. Laboratory investigations showed persistent hypophosphatemia with renal phosphate wasting suggestive of hypophosphatemic osteomalacia. She also had concomitant vitamin D deficiency which contributed to the disease severity. Medical therapy with oral phosphate and vitamin D improved her symptoms without significant changes in fracture healing or phosphate levels.
Hypophosphatemia ; Osteomalacia ; FGF23 ; Vitamin D Deficiency

Pituitary stalk lesions can represent a wide range of pathologies. The exact cause is often unknown due to hesitancy to proceed with biopsy. We present a 16-year-old adolescent who presented with delayed puberty, short stature and bilateral cryptorchidism. He was found to have a thickened pituitary stalk of uncertain etiology with partial hypopituitarism (gonadotrophin and growth hormone deficiency) on further assessment. The presence of bilateral cryptorchidism and micropenis represents lack of “mini puberty,” a phenomenon of activation of the hypothalamic-pituitary-gonadal (HPG) axis in-utero or within the first few months of life.1 These key clinical features have been useful to establish an early temporal relationship and suggest a congenital origin of disease. This enabled a more conservative approach of surveillance to be employed as opposed to invasive pathological examination with pituitary stalk biopsy.
Pituitary Diseases ; Hypopituitarism ; Cryptorchidism ; Growth Hormone

Objective: The primary objective was to assess beta-cell function of recently-diagnosed young-onset type 2 diabetes mellitus (T2DM) individuals using basal and stimulated C-peptide levels. The secondary objective was to examine the association between C-peptide with metabolic factors and diabetes complications. Methodology: A cross-sectional study was conducted for young-onset T2DM individuals aged 18-35 years with a disease duration of not more than 5 years. Plasma C-peptide was measured before and after intravenous glucagon injection. Demographic data, medical history and complications were obtained from medical records and clinical assessment. Continuous data were expressed as median and interquartile range (IQR). Categorical variables were described as frequency or percentage. Multivariable linear regression analysis was used to determine factors associated with C-peptide levels. Results: 113 participants with young-onset T2DM with a median (IQR) age of 29.0 (9.5) years and 24 (36) months were included in this study. The median (IQR) basal and stimulated C-peptide was 619 (655) pmol/L and 1231 (1024) pmol/L. Adequate beta-cell function was present in 78-86% of the participants based on the basal and stimulated C-peptide levels. We found hypertension, obesity and diabetic kidney disease (DKD) to be independently associated with higher C–peptide levels. In contrast, females, smokers, those on insulin therapy and with longer duration of disease had lower C–peptide levels. Conclusion Most recently diagnosed young-onset T2DM have adequate beta-cell function. Elevated C-peptide levels associated with obesity, hypertension and diabetic kidney disease suggest insulin resistance as the key driving factor for complications.
Diabetes Mellitus, Type 2 ; C-Peptide