Managing idiopathic short stature: role of somatropin (rDNA origin) for injection

Growth failure in focal dermal hypoplasia

Focal dermal hypoplasia (FDH) is a rare genetic disorder caused by mutations in the PORCN gene located on the X chromosome. Short stature was previously noted to be a common finding in FDH, however the etiology of this is unclear. The present study sought to elucidate specific causes for short stature by assessing growth charts, determining bone ages and auxologic measurements, examining laboratory data for the common causes of growth failure, assessing dietary intake, and performing a growth hormone stimulation test. Sixteen patients with FDH between the ages of 3 and 18 years of age consented to the study. While 11 out of 16 patients had short stature based on height less than 2 standard deviations below mid-parental target height percentile and bone age not suggestive of likely catch-up growth, only four had a BMI less than the 5th percentile for age. Laboratory studies did not support a gastrointestinal, allergy or autoimmune cause of growth failure. Three patients had results suggestive of possible growth hormone deficiency. Although short stature is a common feature in FDH, our data suggests that severe undernutrition is not common in this group and that there may be underlying treatable causes for this short stature in some patients.

Medicalising short children with growth hormone? Ethical considerations of the underlying sociocultural aspects

In 2003, the Food and Drug Administration approved the use of growth hormone treatment for idiopathic short stature children, i.e. children shorter than average due to an unknown medical cause. Given the absence of any pathological conditions, this decision has been contested as a case of medicalisation. The aim of this paper is to broaden the debate over the reasons for and against the treatment, to include considerations of the sociocultural phenomenon of the medicalisation of short stature, by means of a critical understanding of the concept of medicalisation. After defining my understanding of medicalisation and describing both the treatment and the condition of idiopathic short stature, I will problematise two fundamental issues: the medical/non-medical distinction and the debate about the goals of medicine. I will analyse them, combining perspectives of bioethics, medical sociology, philosophy of medicine and medical literature, and I will suggest that there are different levels of normativity of medicalisation. Ultimately, this study shows that: (1) the definition of idiopathic short stature, focusing only on actual height measurement, does not provide enough information to assess the need for treatment or not; (2) the analysis of the goals of medicine should be broadened to include justifications for the treatment; (3) the use of growth hormone for idiopathic short stature involves strong interests from different stakeholders. While the treatment might be beneficial for some children, it is necessary to be vigilant about possible misconduct at different levels of medicalisation.

Intravenous delivery of adeno-associated virus 9-encoded IGF-1Ea propeptide improves post-infarct cardiac remodelling

The insulin-like growth factor Ea propeptide (IGF-1Ea) is a powerful enhancer of cardiac muscle growth and regeneration, also blocking age-related atrophy and beneficial in multiple skeletal muscle diseases. The therapeutic potential of IGF-1Ea compared with mature IGF-1 derives from its local action in the area of synthesis. We have developed an adeno-associated virus (AAV) vector for IGF-1Ea delivery to the heart to treat mice after myocardial infarction and examine the reparative effects of local IGF-1Ea production on left ventricular remodelling. A cardiotropic AAV9 vector carrying a cardiomyocyte-specific IGF-1Ea-luciferase bi-cistronic gene expression cassette (AAV9.IGF-1Ea) was administered intravenously to infarcted mice, 5 h after ischemia followed by reperfusion (I/R), as a model of myocardial infarction. Virally encoded IGF-1Ea in the heart improved global left ventricular function and remodelling, as measured by wall motion and thickness, 28 days after delivery, with higher viral titers yielding better improvement. The present study demonstrates that single intravenous AAV9-mediated IGF-1Ea Gene Therapy represents a tissue-targeted therapeutic approach to prevent the adverse remodelling after myocardial infarct.

Emerging options in growth hormone therapy: an update

Growth hormone (GH) was first used to treat a patient in 1958. For the next 25 years it was available only from cadaver sources, which was of concern because of safety considerations and short supply. In 1985, GH produced by recombinant DNA techniques became available, expanding its possible uses. Since that time there have been three indications approved by the US Food and Drug Administration (FDA) for GH-deficiency states and nine indications approved for non-GH-deficiency states. In 2003 the FDA approved GH for use in idiopathic short stature (ISS), which may indirectly cover other diagnoses that have short stature as a feature. However, coverage for GH therapy is usually more reliably obtainable for a specific indication, rather than the ISS indication. Possible future uses for GH therapy could include the treatment of syndromes such as Russell-Silver syndrome or chondrodystrophy. Other non-short-stature indications could include wound healing and burns. Other uses that have been poorly studied include aging and physical performance, in spite of the interest already shown by elite athletes in using GH. The safety profile of GH developed over the past 25 years has shown it to be a very safe hormone with few adverse events associated with it. The challenge for the future is to follow these patients into adulthood to determine whether GH therapy poses any long-term risks.