Disorders of sex development-when and how to tell the patient.

Physicians and other providers are often confronted with difficult decisions in the area of disclosure. This article examines a hypothetical situation relevant to the practice of pediatric endocrinology. The parents of a child with a disorder of sex development (DSD) wish the physician to treat their child, but without revealing key medical information to the child. Herein, we will explore the legal and ethical responsibilities of a provider to disclose information to an under-age DSD patient and to provide insight on when and how to tell the patient.

Update on pediatric bone health.

Osteoporosis has long been considered a health problem unique to older adults. Children and adolescents with chronic illness, primary bone disease, or poor nutrition, however, are also predisposed to impaired skeletal health. The present review discusses normal skeletal development, risk factors for low bone mineral density, and prevention and treatment strategies that can help optimize bone health in the pediatric population.

Pediatric dual-energy X-ray absorptiometry: technique, interpretation, and clinical applications.

This article reviews the dual-energy x-ray absorptiometry (DXA) technique, its interpretation, and clinical applications with emphasis on the considerations unique to pediatrics. Specifically, the use of DXA in children requires the radiologist to be a "clinical pathologist," monitoring the technical aspects of the DXA acquisition, a "statistician" knowledgeable in the concepts of Z-scores and least significant changes, and a "bone specialist," aware of the DXA findings in a large number of clinical diseases, providing the referring clinician with a meaningful context for the numeric result obtained with DXA.

Pediatric DXA: clinical applications.

Normal bone mineral accrual requires adequate dietary intake of calcium, vitamin D and other nutrients; hepatic and renal activation of vitamin D; normal hormone levels (thyroid, parathyroid, reproductive and growth hormones); and neuromuscular functioning with sufficient stress upon the skeleton to induce bone deposition. The presence of genetic or acquired diseases and the therapies that are used to treat them can also impact bone health. Since the introduction of clinical DXA in pediatrics in the early 1990s, there has been considerable investigation into the causes of low bone mineral density (BMD) in children. Pediatricians have also become aware of the role adequate bone mass accrual in childhood has in preventing osteoporotic fractures in late adulthood. Additionally, the availability of medications to improve BMD has increased with the development of bisphosphonates. These factors have led to the increased utilization of DXA in pediatrics. This review summarizes much of the previous research regarding BMD in children and is meant to assist radiologists and clinicians with DXA utilization and interpretation.

Isolated neurosarcoidosis presenting as headache and multiple brain and spinal cord lesions mimicking central nervous system metastases.

Sarcoidosis is uncommon in children. Although isolated neurosarcoidosis has been seen in 15% adults with sarcoidosis, pediatric neurosarcoidosis is rarely reported. Neurosarcoidosis may present with cranial neuropathy, including facial palsy, optic nerve or other cranial nerve involvement, peripheral neuropathy, or manifestations of the central nervous system affecting the hypothalamus, pituitary gland, cerebral cortex, cerebellum, meninges, and spinal cord. The useful diagnostic investigations include magnetic resonance imaging of the brain and spinal cord, cerebrospinal fluid studies, brain and meningeal biopsy if feasible, chest radiography to reveal sarcoidosis, angiotensin-converting enzyme level in the serum or cerebrospinal fluid, and Kveim test when available. We herein report a case of isolated brain biopsy-confirmed neurosarcoidosis in a 17-year-old boy presenting with severe unilateral headache and multiple brain and spinal cord MRI lesions mimicking central nervous system metastases.

Primary pigmented nodular adrenocortical disease reveals insulin-like growth factor binding protein-2 regulation by protein kinase A.

OBJECTIVE: Primary pigmented nodular adrenocortical disease (PPNAD) can occur as an isolated trait or part of Carney complex, a familial lentiginosis-multiple endocrine neoplasia syndrome frequently caused by mutations in PRKAR1A, which encodes the 1alpha regulatory subunit of protein kinase A (PKA). Because alterations in the insulin-like growth factor (IGF) axis, particularly IGF-II and IGF binding protein (IGFBP)-2 overexpression, have been implicated in sporadic adrenocortical tumors, we sought to examine the IGF axis in PPNAD. DESIGN: RNA samples and paraffin-embedded sections were procured from adrenalectomy specimens of patients with PPNAD. Changes in expression of IGF axis components were evaluated by real-time quantitative RT-PCR and immunohistochemistry. NCI-H295R cells were used to study PKA and IGF axis signaling in adrenocortical cells in vitro. RESULTS: IGFBP-2 mRNA level distinguished between the two genetic subtypes of this disease; increased IGFBP-2 expression in PRKAR1A mutation-positive PPNAD tissues was also confirmed by immunohistochemistry. Moreover, PKA inhibitors increased IGFBP-2 expression in NCI-H295R adrenocortical cells, and anti-IGFBP-2 antibody reduced their proliferation. CONCLUSIONS: IGFBP-2 expression is increased in PPNAD caused by PRKAR1A mutations, and in adrenocortical cancer cells. This is the first evidence for PKA-dependent regulation of IGFBP-2 expression in adrenocortical cells.

Pediatric DXA: technique and interpretation.

This article reviews dual X-ray absorptiometry (DXA) technique and interpretation with emphasis on the considerations unique to pediatrics. Specifically, the use of DXA in children requires the radiologist to be a "clinical pathologist" monitoring the technical aspects of the DXA acquisition, a "statistician" knowledgeable in the concepts of Z-scores and least significant changes, and a "bone specialist" providing the referring clinician a meaningful context for the numeric result generated by DXA. The patient factors that most significantly influence bone mineral density are discussed and are reviewed with respect to available normative databases. The effects the growing skeleton has on the DXA result are also presented. Most important, the need for the radiologist to be actively involved in the technical and interpretive aspects of DXA is stressed. Finally, the diagnosis of osteoporosis should not be made on DXA results alone but should take into account other patient factors.

Reconciling diabetes management and the ketogenic diet in a child with pyruvate dehydrogenase deficiency.

A 4-year-old girl with pyruvate dehydrogenase deficiency, static encephalopathy, and seizure disorder treated with the ketogenic diet presented in severe diabetic ketoacidosis. Pyruvate dehydrogenase deficiency is a rare genetic defect of mitochondrial energy metabolism that leads to inefficient glucose use and lactic acidosis. The ketogenic diet provides the brain with an alternate fuel source, but its implementation opposes traditional diabetes management. Faced with this therapeutic dilemma, we aimed to maintain ketosis without compromising safety to optimize neurologic function and quality of life. This is the first report, to our knowledge, of a child simultaneously treated with the ketogenic diet and exogenous insulin. A 28-month follow-up revealed excellent glycemic control, improved activity level, significant developmental achievements, and, perhaps most striking, catch-up linear growth from < 5th percentile to the 50th percentile. Her progress to date indicates that diabetes does not preclude use of the ketogenic diet.

Genotype-phenotype correlations in children with congenital hyperinsulinism due to recessive mutations of the adenosine triphosphate-sensitive potassium channel genes.

Congenital hyperinsulinism (HI) is most commonly caused by recessive mutations of the pancreatic beta-cell ATP-sensitive potassium channel (K(ATP)), encoded by two genes on chromosome 11p, SUR1 and Kir6.2. The two mutations that have been best studied, SUR1 g3992-9a and SUR1 delF1388, are null mutations yielding nonfunctional channels and are characterized by nonresponsiveness to diazoxide, a channel agonist, and absence of acute insulin responses (AIRs) to tolbutamide, a channel antagonist, or leucine. To examine phenotypes of other K(ATP) mutations, we measured AIRs to calcium, leucine, glucose, and tolbutamide in infants with recessive SUR1 or Kir6.2 mutations expressed as diffuse HI (n = 8) or focal HI (n = 14). Of the 24 total mutations, at least seven showed evidence of residual K(ATP) channel function. This included positive AIR to both tolbutamide and leucine in diffuse HI cases or positive AIR to leucine in focal HI cases. One patient with partial K(ATP) function also responded to treatment with the channel agonist, diazoxide. Six of the seven patients with partial defects had amino acid substitutions or insertions; whereas, the other patient was compound heterozygous for two premature stop codons. These results indicate that some K(ATP) mutations can yield partially functioning channels, including cases of hyperinsulinism that are fully responsive to diazoxide therapy.

Expanded spectrum of recombinant human growth hormone therapy.

The efficacy of recombinant human growth hormone in the treatment of growth hormone deficiency is well established. In recent years, the use of recombinant human growth hormone as a therapeutic modality has greatly increased and has expanded beyond the realm of replacement for growth hormone deficiency. Recombinant human growth hormone has been employed to ameliorate growth failure in multiple other disorders. For some, like Turner syndrome, recombinant human growth hormone has become the standard of care. For others, the ultimate benefit of recombinant human growth hormone remains to be determined. Although recent investigations provide encouraging short-term data, it is important to recognize that the impact of recombinant human growth hormone therapy on adult height has not been established in a number of conditions.