MECHANISMS IN ENDOCRINOLOGY: Novel genetic causes of short stature.

The fast technological development, particularly single nucleotide polymorphism array, array-comparative genomic hybridization, and whole exome sequencing, has led to the discovery of many novel genetic causes of growth failure. In this review we discuss a selection of these, according to a diagnostic classification centred on the epiphyseal growth plate. We successively discuss disorders in hormone signalling, paracrine factors, matrix molecules, intracellular pathways, and fundamental cellular processes, followed by chromosomal aberrations including copy number variants (CNVs) and imprinting disorders associated with short stature. Many novel causes of GH deficiency (GHD) as part of combined pituitary hormone deficiency have been uncovered. The most frequent genetic causes of isolated GHD are GH1 and GHRHR defects, but several novel causes have recently been found, such as GHSR, RNPC3, and IFT172 mutations. Besides well-defined causes of GH insensitivity (GHR, STAT5B, IGFALS, IGF1 defects), disorders of NFκB signalling, STAT3 and IGF2 have recently been discovered. Heterozygous IGF1R defects are a relatively frequent cause of prenatal and postnatal growth retardation. TRHA mutations cause a syndromic form of short stature with elevated T3/T4 ratio. Disorders of signalling of various paracrine factors (FGFs, BMPs, WNTs, PTHrP/IHH, and CNP/NPR2) or genetic defects affecting cartilage extracellular matrix usually cause disproportionate short stature. Heterozygous NPR2 or SHOX defects may be found in ∼3% of short children, and also rasopathies (e.g., Noonan syndrome) can be found in children without clear syndromic appearance. Numerous other syndromes associated with short stature are caused by genetic defects in fundamental cellular processes, chromosomal abnormalities, CNVs, and imprinting disorders.

The many faces of rare diseases (RD): meeting report on Rare Disease in South-Eastern Europe, 15-16 November 2013, Skopje, Republic of Macedonia.

The Second meeting on Rare Diseases in South Eastern Europe (SEE) was held in Skope, Macedonia on November 15-16, 2013. Objective and main data: Rare diseases (RD) are a major problem in developed and especially in countries without affluence. 6-8% of every population suffers from RD. The cumulative effect of RDs on the health system of a country is increasing. Diagnosis often remains a challenge and requires international collaboration. Treatment in diseases for which medication exist is often inaccessible to patients because of the high costs. All countries of SEE need screening programs that address more diseases. Patient organizations play a major role in increasing awareness and providing the needed pressure on society to treat treatable RDs. On the other hand, RDs are frequently a source of valuable new molecular insights not only on mechanisms of their etiology and pathology, but sometimes provide an insight on mechanisms of frequent diseases in man. Further efforts are needed in improving all the RD aspects mentioned.

Mecasermin: new drug. Insufficient improvement in statural growth.

(1) Human insulin-like growth factor type 1 (IGF-1) is the main effector of growth hormone action. Primary IGF-1 deficiency is a rare disease, mainly resulting in very short stature; (2) Mecasermin is a recombinant IGF-1 marketed for this indication as a twice daily subcutaneous injection; (3) Clinical evaluation is mainly based on a non-comparative follow-up study of 76 children with an average age of 7 years, some of whom were treated for 8 years. The mean height at treatment initiation was 6.7 standard deviations below normal. Eight years later, it was 5.2 standard deviations below normal, i.e. their growth failure remained very severe; (4) The main short-term adverse effects of mecasermin are hypoglycaemia, headache and intracranial hypertension. Nearly one in 5 children developed tonsillar hypertrophy, resulting in otitis and hypoacusis; (5) Animal studies showed hypertrophy of other organs (kidneys, spleen and heart) as well as carcinogenic effects. The risk in humans is unknown; (6) The mecasermin packaging is not well-adapted (a multidose vial designed to be punctured several times), and is a potential source of contamination and errors. Prefilled pens or syringes would be easier to use; (7) In practice, the limited clinical benefits of mecasermin do not justify exposure to its potential risks.

Multiple hormonal deficiencies in anabolic hormones are found in frail older women: the Women's Health and Aging studies.

BACKGROUND: Alterations in anabolic hormones are theorized to contribute to aging and frailty, with most studies focusing on the relationship between individual hormones and specific age-associated diseases. We hypothesized that associations with frailty would most likely manifest in the presence of deficits in multiple anabolic hormones. METHODS: The relationships of serum levels of total IGF-1, DHEAS, and free testosterone (T) with frailty status (nonfrail, prefrail, or frail) were analyzed in 494 women aged 70-79 years enrolled in the Women's Health and Aging Studies I or II. Using multivariate polytomous regression, we calculated the odds of frailty for deficiency in each hormone (defined as the bottom quartile of the hormone) individually, as well as for a count of the hormones. RESULTS: For each hormone, in adjusted analyses, those with the deficiency were more likely to be frail than those without the deficiency, although this did not achieve statistical significance (IGF-1: odds ratio [OR] 1.82, confidence interval [CI] 0.81-4.08; DHEAS: OR 1.68, CI 0.77-3.69; free T: OR 2.03, CI 0.89-4.64). Compared with those with no hormonal deficiencies, those with one deficiency were not more likely to be frail (OR 1.15, CI 0.49-2.68), whereas those with two or three deficiencies had a very high likelihood of being frail (OR 2.79, CI 1.06-7.32), in adjusted models. CONCLUSIONS: The absolute burden of anabolic hormonal deficiencies is a stronger predictor of frailty status than the type of hormonal deficiency, and the relationship is nonlinear. These analyses suggest generalized endocrine dysfunction in the frailty syndrome.

Assessment and treatment of short stature in pediatric patients with chronic kidney disease: a consensus statement.

Growth failure is a clinically important issue in children with chronic kidney disease (CKD) and is associated with significant morbidity and mortality. Many factors contribute to impaired growth in these children, including abnormalities in the growth hormone (GH)-insulin-like growth factor-I (IGF-I) axis, malnutrition, acidosis, and renal bone disease. The management of growth failure in children with CKD is complicated by the presence of other disease-related complications requiring medical intervention. Despite evidence of GH efficacy and safety in this population, some practitioners and families have been reluctant to institute GH therapy, citing an unwillingness to comply with daily injections, reimbursement difficulties, or impending renal transplantation. Suboptimal attention to growth failure management may be further compounded by a lack of clinical guidelines for the appropriate assessment and treatment of growth failure in these children. This review of growth failure in children with CKD concludes with an algorithm developed by members of the consensus committee, outlining their recommendations for appropriate steps to improve growth and overall health outcomes in children with CKD.