RESUMEN
The widespread use of supplemental vitamin D has dramatically reduced the incidence of rickets. While generally considered a safe practice, there is potential for toxicity in patients with idiopathic infantile hypercalcemia (IIH). Inadequate 24-hydroxylase-enzyme activity renders these individuals unable to degrade active vitamin D, resulting in hypercalcemia due to increased intestinal calcium absorption, decreased renal calcium excretion, and increased osteoclastic bone activity. Clinicians should be aware that even therapeutic doses of vitamin D can prove harmful for patients with CYP24A1 mutations. Studies have also demonstrated a link between inadequate 24-hydroxylase activity and nephrocalcinosis, renal insufficiency, and calcium containing kidney stones, further emphasizing the importance of early recognition of this disease and judicious use of vitamin D. We present a case with an interesting diagnostic algorithm used to diagnose IIH when given an incomplete history and subsequently review the existing literature on the subject.
Asunto(s)
Hipercalcemia/diagnóstico , Humanos , Hipercalcemia/fisiopatología , Lactante , MasculinoRESUMEN
Pseudotumor cerebri (PTC) is an uncommon disorder in the pediatric population. It is not a benign condition. It can cause permanent vision loss. The most recently recognized risk factor for this disorder is recombinant human growth hormone (GH) therapy. Data from Genentech's National Cooperative Growth Study (NCGS), a postmarketing surveillance program, are analyzed to examine the relationship between GH therapy and PTC. Several areas are addressed, including plausibility, probability, clinical and laboratory presentations, management, clinical outcome, present state of knowledge, and future recommendations.
Asunto(s)
Hormona del Crecimiento/efectos adversos , Seudotumor Cerebral/inducido químicamente , Seudotumor Cerebral/epidemiología , Adolescente , Factores de Edad , Índice de Masa Corporal , Niño , Preescolar , Bases de Datos Factuales , Relación Dosis-Respuesta a Droga , Femenino , Hormona del Crecimiento/administración & dosificación , Humanos , Masculino , Obesidad/complicaciones , Obesidad/epidemiología , Seudotumor Cerebral/diagnóstico , Factores de Riesgo , Resultado del Tratamiento , Estados Unidos/epidemiologíaAsunto(s)
Anomalías Múltiples/genética , Anomalías Múltiples/terapia , Genes ras , Anomalías Múltiples/fisiopatología , Sulfatos de Condroitina/metabolismo , Anomalías Craneofaciales/genética , Inhibidores Enzimáticos/uso terapéutico , Farnesiltransferasa/antagonistas & inhibidores , Genotipo , Mutación de Línea Germinal , Cardiopatías Congénitas/genética , Hormona de Crecimiento Humana/uso terapéutico , Humanos , Neoplasias/genética , Fenotipo , SíndromeRESUMEN
OBJECTIVE: To study the NKX2-1 gene in two half-siblings with elevated thyroid-stimulating hormone (TSH) on state screen, prolonged neonatal respiratory distress despite term gestations, and persistent ataxia, dysarthria, and developmental delay. STUDY DESIGN: We amplified and sequenced DNA samples from blood or buccal swab for subjects and their unaffected siblings. RESULTS: The same mutation that prevents splicing together of exons 2 and 3 of the NKX2-1 gene was present in the affected siblings, their mother, and maternal grandmother but not in their unaffected siblings. The mutation was present in the heterozygous form, thus explaining the disease phenotype. CONCLUSIONS: Autosomal dominant transmission of mutations of NKX2-1 may cause congenital hypothyroidism, neonatal respiratory distress at term, and persistent neurologic findings such as ataxia, choreoathetosis, and dysarthria in families with affected subjects in multiple generations.