A 15-year-old boy’s growth chart is reviewed, showing a normal pubertal growth spurt. You explain to a medical student that growth hormone (GH) is secreted in a pulsatile fashion, regulated by hypothalamic hormones. The peaks of GH secretion occur when peaks of Growth Hormone-Releasing Hormone (GHRH) coincide with troughs of which other hypothalamic hormone?
An 17-year-old female presents with the chief complaint of never having had a menstrual period and no breast development. She is of normal stature and has no dysmorphic features. Her karyotype is 46,XX. Laboratory investigations reveal markedly elevated follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels. A pelvic ultrasound shows a normal uterus but only streak ovaries. What is the most likely diagnosis?
A 12-year-old boy was diagnosed with type 1 diabetes mellitus at age 8. He is doing well on an insulin pump, with his most recent HbA1c at 7.2%. During his routine follow-up visit, when should the initial screening for diabetic retinopathy be performed?
A 6-week-old male infant is seen for a routine well-child visit. A set of screening labs, drawn for an unrelated reason, reveals an elevated luteinizing hormone (LH) and a testosterone level that is higher than typical prepubertal values. The infant is thriving, and his physical exam, including normal male genitalia, is unremarkable. What is the most likely explanation for these hormonal findings?
A 16-year-old female presents with a 6-month history of secondary amenorrhea and new-onset galactorrhea. Her serum prolactin level is elevated at 90 ng/mL. An MRI of the brain reveals a 0.8 cm pituitary microadenoma consistent with a prolactinoma. What is the first-line treatment for this patient?
During early embryonic development, the fetal gonad is bipotential, meaning it has the capacity to develop into either a testis or an ovary. The expression of the SRY gene on the Y chromosome is the critical molecular switch that directs the gonad toward testicular differentiation. In a fetus with a 46,XX chromosomal complement, what is the default developmental pathway for the bipotential gonad in the absence of SRY?
A 17-year-old female presents with several weeks of neck pain, low-grade fever, and palpitations. Laboratory tests show a suppressed thyrotropin (TSH), elevated free thyroxine (T4), and a markedly elevated erythrocyte sedimentation rate (ESR). A radioiodine uptake study shows depressed uptake. What is the most likely diagnosis?
A newborn female is noted to have prominent edema of the dorsa of her hands and feet and loose skinfolds at the nape of her neck. A diagnosis of Turner syndrome is confirmed by karyotype analysis. According to clinical guidelines, which associated anomaly must be screened for at the time of diagnosis, regardless of the patient’s age or absence of symptoms?
A newborn screening program that measures thyroxine (T4) as the primary test identifies a male infant with a total T4 of 2.5 μg/dL (low). A follow-up test shows a normal thyrotropin (TSH) and a normal free T4 level. The infant is clinically well and thriving. What is the most likely diagnosis?
A 12-year-old male with new-onset type 1 diabetes mellitus presents with diabetic ketoacidosis. A recent randomized trial comparing different fluid management strategies in children with diabetic ketoacidosis found no difference in short- or long-term neurocognitive outcomes between which of the following treatment arms?