Evidence of intrauterine growth restriction and growth hormone deficiency in 49,XXXXY syndrome.

49,XXXXY is an X and Y chromosome variation that occurs in 1:85,000 to 1:100,000 live male births. Previous case studies have described boys with this disorder to be shorter than average when compared with boys with only one extra chromosome and with the mean stature in a small cohort reported to range from the seventh to 33rd percentile. The origin behind the possible differences in height between boys with 47,XXY and 49,XXXXY is currently unknown, however one study hypothesized that it was due to a difference in the expression of the SHOX gene. This study reports on the anthropometric measurements of 84 boys with 49,XXXXY. Forty-five percent of children with 49,XXXXY were found to be below the third percentile in height at the time of evaluation. In addition, 7.14% of the cohort were diagnosed and given treatment for growth hormone deficiency (GHD). The analysis of this cohort demonstrates that the below average heights seen throughout childhood in this population potentially begins prenatally and suggests that boys with 49,XXXXY may be at a higher risk for intrauterine growth restriction (IUGR) and GHD. Future research is needed to investigate the etiology of the poor growth in boys with 49,XXXXY and evaluate the incidence of GHD and IUGR in this population.

Update On The Clinical Perspectives And Care Of The Child With 47,XXY (Klinefelter Syndrome).

47,XXY (Klinefelter syndrome [KS]) is the most common sex chromosomal aneuploidy (1:660), yet, despite this, only 25% of the males are ever diagnosed. Males with 47,XXY present with characteristic symptoms throughout their lifetime with typical physical and neurodevelopmental manifestations focused in growth, cognitive development, endocrine function, and reproduction. Studies have demonstrated that optimal outcomes are dependent on early detection combined with consistent and targeted neurodevelopmental treatment throughout the lifespan. During infancy and into the preschool years, individuals with 47,XXY commonly face deficits in growth and development in the areas of early hormonal, motor, speech, and behavioral development. As they transition into school, the primary neurodevelopmental concerns include language difficulty, executive dysfunction, behavior, and learning and reading deficits. Adults with 47,XXY often present with taller than average height, low levels of fertility, azoospermia, and elevated gonadotropin levels. These presentations may persist from early childhood through adulthood but can be mitigated by appropriate interventions. Early neurodevelopmental and hormonal treatment has been shown to have a minimizing effect on the physical and neurodevelopmental manifestations in individuals with 47,XXY. With innovative and current research studies, the features common to the neurodevelopmental profile of 47,XXY have been further expanded and defined. Further research is necessary to elucidate and understand the relationship between the brain, behavior, and the phenotypic profile of 47,XXY.

Short Stature in Chronic Kidney Disease Treated with Growth Hormone and an Aromatase Inhibitor.

We describe an alternative strategy for management of severe growth failure in a 14-year-old child who presented with advanced chronic kidney disease close to puberty. The patient was initially treated with growth hormone for a year until kidney transplantation, followed immediately by a year-long course of an aromatase inhibitor, anastrozole, to prevent epiphyseal fusion and prolong the period of linear growth. Outcome was excellent, with successful transplant and anticipated complete correction of height deficit. This strategy may be appropriate for children with chronic kidney disease and short stature who are in puberty.

A 4-Year, Open-Label, Multicenter, Randomized Trial of Genotropin® Growth Hormone in Patients with Idiopathic Short Stature: Analysis of 4-Year Data Comparing Efficacy, Efficiency, and Safety between an Individualized, Target-Driven Regimen and Standard Dosing.

BACKGROUND/AIMS: Growth hormone (GH) treatment regimens for children with non-GH-deficient, idiopathic short stature (ISS) have not been optimized. To compare the efficacy, efficiency, and safety of an individualized, target-driven GH regimen with standard weight-based dosing after 4 years of treatment. METHODS: This is a 4-year, open-label, multicenter, randomized trial comparing individualized, formula-based dosing of Genotropin® versus a widely used ISS dose of Genotropin®. Subjects were prepubertal, had a bone age of 3-10 years for males and 3-9 years for females, were naive to GH treatment, and had a height standard deviation score (Ht SDS) of -3 to -2.25, a height velocity <25th percentile for their bone age, and peak stimulated GH >10 ng/ml. After the first 2 years, the individualized-dosing group was further randomized to either 0.18 or 0.24 mg/kg/week. RESULTS: At 4 years, subjects in all treatment regimens achieved similar average height gains of +1.3 SDS; however, the individualized dosing regimen utilized less GH to achieve an equivalent height gain. CONCLUSION: Individualized, formula-based GH dosing, followed by a dose reduction after 2 years, provides a more cost-effective growth improvement in patients with ISS than currently employed weight-based regimens.

Kv1.3 channels are a therapeutic target for T cell-mediated autoimmune diseases.

Autoreactive memory T lymphocytes are implicated in the pathogenesis of autoimmune diseases. Here we demonstrate that disease-associated autoreactive T cells from patients with type-1 diabetes mellitus or rheumatoid arthritis (RA) are mainly CD4+ CCR7- CD45RA- effector memory T cells (T(EM) cells) with elevated Kv1.3 potassium channel expression. In contrast, T cells with other antigen specificities from these patients, or autoreactive T cells from healthy individuals and disease controls, express low levels of Kv1.3 and are predominantly naïve or central-memory (T(CM)) cells. In T(EM) cells, Kv1.3 traffics to the immunological synapse during antigen presentation where it colocalizes with Kvbeta2, SAP97, ZIP, p56(lck), and CD4. Although Kv1.3 inhibitors [ShK(L5)-amide (SL5) and PAP1] do not prevent immunological synapse formation, they suppress Ca2+-signaling, cytokine production, and proliferation of autoantigen-specific T(EM) cells at pharmacologically relevant concentrations while sparing other classes of T cells. Kv1.3 inhibitors ameliorate pristane-induced arthritis in rats and reduce the incidence of experimental autoimmune diabetes in diabetes-prone (DP-BB/W) rats. Repeated dosing with Kv1.3 inhibitors in rats has not revealed systemic toxicity. Further development of Kv1.3 blockers for autoimmune disease therapy is warranted.

Growth hormone deficiency in HIV-infected children following successful treatment with highly active antiretroviral therapy.

Growth failure is common in children with untreated HIV, although growth hormone (GH) deficiency is rare. Treatment with highly active antiretroviral therapy usually results in resumption of normal growth. We report the cases of 2 children with growth failure despite stable full suppression of viremia who were found to be GH deficient.