Cost-effectiveness of somatrogon in the Spanish pediatric population with growth hormone deficiency

OBJECTIVE

To analyze the cost-effectiveness of weekly somatrogon compared to daily growth hormones (GH-d) in the pediatric population of Spain with growth hormone deficiency (GHD).

METHODS

Markov model with two states (patients with or without GH-d or somatrogon treatment) in prepubertal children (3 to 11 years and 3 to 12 years in girls and boys, respectively) with GHD in isolation or as part of multiple pituitary hormone deficiency and without previous treatment, from the perspective of the National Health System. The simulation of the economic model ends at the age of 18. The costs of hormones and monitoring were obtained from Spanish sources. The utilities were obtained from the literature. Spanish clinical experts validated the assumptions of the model.

RESULTS

In the deterministic analysis, somatrogon would be cost-effective, compared to GH-d, with a cost per QALY (quality-adjusted life year) gained of €19,259 and a clinically relevant QALY gain (0.336). This result was confirmed in deterministic sensitivity analyses. According to the probabilistic analysis, somatrogon would be the dominant treatment, with a 61% probability of a willingness to pay of €25,000 per QALY gained.

CONCLUSION

Compared to GH-d, somatrogon is cost-effective in the Spanish pediatric population with GHD.

Congenital hyperinsulinism in two siblings with ABCC8 mutation: same genotype, different phenotypes

Congenital hyperinsulinism (CHI) is a heterogenous disease caused by insulin secretion regulatory defects, being ABCC8/KCNJ11 the most commonly affected genes. Therapeutic options include diazoxide, somatostatin analogues and surgery, which is curative in focal CHI. We report the case of two siblings (born two years apart) that presented themselves with hypoketotic hyperinsulinemic persistent hypoglycemias during neonatal period. The diagnosis of diffuse CHI due to an ABCC8 compound mutation (c.3576delG and c.742C>T) was concluded. They did not benefit from diazoxide therapy (or pancreatectomy performed in patient number 1) yet responded to somatostatin analogues. Patient number 1 developed various neurological deficits (including epilepsy), however patient number 2 experienced an entirely normal neurodevelopment. We believe this case shows how previous knowledge of the firstborn sibling's disease contributed to a better and timelier medical care in patient number 2, which could potentially explain her better neurological outcome despite their same genotype.

Severe neurological abnormalities in a young boy with impaired thyroid hormone sensitivity due to a novel mutation in the MCT8 gene

Monocarboxylate transporter 8 (MCT8) is an active and specific thyroid hormone transporter into neurons. MCT8 mutations cause an X-linked condition known as Allan-Herndon-Dudley syndrome and are characterized by impaired psychomotor development and typical abnormal thyroid function. We describe a 10-year-old boy with severe cognitive disability, axial hypotonia, spastic quadriplegia and sporadic dyskinetic episodes. He initially presented with thyroid dysfunction (high FT3, low rT3, low FT4 and normal TSH) and generalized retardation of the cerebral and cerebellar myelination in brain magnetic resonance imaging. The clinical and laboratory findings led to sequencing of the SLC16A2/MCT8 gene, which identified a novel missense mutation in exon 5. The study of peripheral markers of thyroid function suggests a paradoxical state of thyrotoxicosis in some peripheral tissues. Our patient had a typical clinical presentation at birth but because of the rarity of his disease his diagnosis was not made until the age of 7. The delay can also be explained by the omission of the free T3 assay in the first thyroid evaluation performed. This case therefore highlights the possible benefit of including the T3 assay in the study of patients with severe psychomotor disability of unknown etiology, thus eliminating extra costs for unnecessary complementary diagnostic tests.

Evolutionary analyses of entire genomes do not support the association of mtDNA mutations with Ras/MAPK pathway syndromes

Background

There are several known autosomal genes responsible for Ras/MAPK pathway syndromes, including Noonan syndrome (NS) and related disorders (such as LEOPARD, neurofibromatosis type 1), although mutations of these genes do not explain all cases. Due to the important role played by the mitochondrion in the energetic metabolism of cardiac muscle, it was recently proposed that variation in the mitochondrial DNA (mtDNA) genome could be a risk factor in the Noonan phenotype and in hypertrophic cardiomyopathy (HCM), which is a common clinical feature in Ras/MAPK pathway syndromes. In order to test these hypotheses, we sequenced entire mtDNA genomes in the largest series of patients suffering from Ras/MAPK pathway syndromes analyzed to date (n = 45), most of them classified as NS patients (n = 42).

Methods/Principal Findings

The results indicate that the observed mtDNA lineages were mostly of European ancestry, reproducing in a nutshell the expected haplogroup (hg) patterns of a typical Iberian dataset (including hgs H, T, J, and U). Three new branches of the mtDNA phylogeny (H1j1, U5b1e, and L2a5) are described for the first time, but none of these are likely to be related to NS or Ras/MAPK pathway syndromes when observed under an evolutionary perspective. Patterns of variation in tRNA and protein genes, as well as redundant, private and heteroplasmic variants, in the mtDNA genomes of patients were as expected when compared with the patterns inferred from a worldwide mtDNA phylogeny based on more than 8700 entire genomes. Moreover, most of the mtDNA variants found in patients had already been reported in healthy individuals and constitute common polymorphisms in human population groups.

Conclusions/Significance

As a whole, the observed mtDNA genome variation in the NS patients was difficult to reconcile with previous findings that indicated a pathogenic role of mtDNA variants in NS.

Central precocious puberty in children living in Spain: incidence, prevalence, and influence of adoption and immigration

CONTEXT

No epidemiological data are available on central precocious puberty (CPP) in the general population or in adopted or immigrant children in Spain.

OBJECTIVE

We aimed to study the incidence and prevalence of CPP, assess the risk of developing this disorder among adopted and immigrant children, and analyze the predictive variables of CPP associated with intracranial pathology.

DESIGN, SETTINGS, AND PATIENTS

An observational study of children diagnosed with CPP in Spain was carried out between January 2008 and January 2010. A computer program was designed to process clinical and biological data and information on 250 patients treated in 34 pediatric endocrinology units throughout the country.

RESULTS

Of the patients registered, 226 were girls and 24 were boys. The global incidence rate of CPP was 5.66 cases per million person-years at risk, with an annual incidence ranging between 0.02 and 1.07 new cases per 100,000. The relative risk of CPP in domestic and internationally adopted children compared with those born in Spain was 27.82 (19.99-38.77), whereas the relative risk among immigrants was 1.55 (0.97-2.38). A logistic regression model developed for the study showed that the combined effect of four variables had a significant influence over the presence of organic disease: being male, having been adopted, age at diagnosis, and estimation of adult height.

CONCLUSIONS

CPP is a rare disease whose risk markedly increases with both national and international adoption but is not influenced by immigration. These results suggest a psychological influence on CPP.

Functional consequences of seven novel mutations in the CYP11B1 gene: four mutations associated with nonclassic and three mutations causing classic 11{beta}-hydroxylase deficiency

CONTEXT

Steroid 11beta-hydroxylase (CYP11B1) deficiency (11OHD) is the second most common form of congenital adrenal hyperplasia (CAH). Cases of nonclassic 11OHD are rare compared with the incidence of nonclassic 21-hydroxylase deficiency.

OBJECTIVE

The aim of the study was to analyze the functional consequences of seven novel CYP11B1 mutations (p.M88I, p.W116G, p.P159L, p.A165D, p.K254_A259del, p.R366C, p.T401A) found in three patients with classic 11OHD, two patients with nonclassic 11OHD, and three heterozygous carriers for CYP11B1 mutations.

METHODS

We conducted functional studies employing a COS7 cell in vitro expression system comparing wild-type (WT) and mutant CYP11B1 activity. Mutants were examined in a computational three-dimensional model of the CYP11B1 protein.

RESULTS

All mutations (p.W116G, p.A165D, p.K254_A259del) found in patients with classic 11OHD have absent or very little 11beta-hydroxylase activity relative to WT. The mutations detected in patients with nonclassic 11OHD showed partial functional impairment, with one patient being homozygous (p.P159L; 25% of WT) and the other patient compound heterozygous for a novel mild p.M88I (40% of WT) and the known severe p.R383Q mutation. The two mutations detected in heterozygous carriers (p.R366C, p.T401A) also reduced CYP11B1 activity by 23 to 37%, respectively.

CONCLUSION

Functional analysis results allow for the classification of novel CYP11B1 mutations as causative for classic and nonclassic 11OHD, respectively. Four partially inactivating mutations are predicted to result in nonclassic 11OHD. These findings double the number of mild CYP11B1 mutations previously described as associated with mild 11OHD. Our data are important to predict phenotypic expression and provide important information for clinical and genetic counseling in 11OHD.

Hypochondroplasia and Acanthosis nigricans: a new syndrome due to the p.Lys650Thr mutation in the fibroblast growth factor receptor 3 gene?

BACKGROUND

Hypochondroplasia (HCH) is a skeletal dysplasia inherited in an autosomal dominant manner due, in most cases, to mutations in the fibroblast growth factor receptor 3 (FGFR3). Acanthosis nigricans (AN) is a velvety and papillomatous pigmented hyperkeratosis of the skin, which has been recognized in some genetic disorders more severe than HCH involving the FGFR3 gene.

OBJECTIVE AND DESIGN

After initial study of the proband, who had been consulted for short stature and who also presented AN, the study was extended to the patient's mother and to 12 additional family members.

METHODS

Clinical, biochemical and radiological studies were performed on the family. In addition, exons 11 and 13 of FGFR3 were analyzed.

RESULTS

The proband and ten relatives presented HCH plus AN and the analysis of FGFR3 showed the p.Lys650Thr mutation. The members with normal phenotypes were non-carriers of the mutation.

CONCLUSION

This is the first report of a large pedigree with the clinical phenotype of HCH plus AN due to a FGFR3 mutation, p.Lys650Thr. This finding demonstrates the coexistence of both conditions due to the same mutation and it might represent a true complex, which should be further established by searching for AN in mild HCH patients or for HCH in patients with AN.

Endocrine disruptors

Man does not come into the world pre-determined. The lifetime set of environmental conditions impinging on a given individual has been termed the ambiome, which together with the genome and the proteome determines each individual's development and construction. Among the most important elements making up the ambiome are endocrine disruptors. An endocrine disruptor is a chemical substance that has adverse effects on an organism or its progeny, through the endocrine system. The number of known endocrine disruptors is large and continuously increasing, and includes both naturally occurring and synthetic substances. We are convinced that they entail genuine problems; although it is difficult to assess their magnitude and real significance, and we will certainly need some time, probably several decades, to obtain conclusive results; but even so, we consider that the existing body of evidence about effects of endocrine disruptors on human health is sufficiently worrying to justify precautionary measures.

Papillary thyroid carcinoma after recombinant GH therapy for Turner syndrome

Turner syndrome (TS) has been included for several years among the indications for GH treatment, generally with satisfactory outcomes. Nevertheless, the long-term effects of this treatment in non-GH deficient patients are not fully known. The incidence of thyroid carcinoma is rare in patients during childhood, it is unusual to find this neoplasia in children under sixteen years old. This article reports the cases of two Spanish patients with papillary thyroid carcinoma after GH treatment for TS. Recent studies have indicated a possible relationship between the GH-IGF axis and the pathogenesis of neoplasias, questioning the chance association of these two pathologies. In line with this, we detected GH receptor expression in the papillary carcinoma cells. Long-term prospective studies are required to clarify the possible effects of GH treatment on the risk of neoplasia.

Kallmann's syndrome with a novel missense mutation in the KAL1 gene that modifies the major cell adhesion site of the anosmin-1 protein

Kallmann's syndrome (KS) refers to the association of hypogonadic hypogonadism and anosmia or hyposmia. The X-linked form of the disease is due to mutations in the KAL1 gene that encodes for the protein anosmin-1. We studied the KAL1 gene in a patient with KS and his family by PCR amplification and direct sequencing. A novel missense mutation (V263G) that modifies the major cell adhesion site of the anosmin-1 protein was identified. Our results suggest that this reported mutation is responsible for KS and might help to elucidate the function of an important area of the anosmin-1 protein.

Genetic basis of short stature

Growth in humans is a complex process controlled by many genetic and non-genetic factors. It is influenced by endogenous factors like genetics, hormones and metabolism as well as exogenous ones like nutrition, physical activity and psychosocial status. Growth is one of the most sensitive markers of children's health, their nutritional status and genetic background. Besides, deviation from normality may be the first manifestation of an underlying congenital or acquired pathology. Thus, it is important to know the growth process and the disorder that can disturb it. Short stature is defined as a condition in which the height of an individual is more than 2 SD below the corresponding mean height for a given age, sex and population group. This disorder is a major concern for patients and their parents, and represents a diagnostic challenge to the clinician. A correct diagnosis is particularly important in view of the availability of effective, but costly, therapy in a small subset of cases. Cytogenetic and molecular analysis can be of great value in this diagnostic process. Emphasis can be made on the advances of molecular genetics, which have characterized human genes involved in the hypothalamus-pituitary-GH axis such as GH, POU1F1, PROP1, GHRHR, GHR, IGF, IGFR, HESX1, LHX3, LHX4, among others. Our current line of investigation is related to the study of some of these genes and the genotype-phenotype relation with the aim of identifying features that add some more light on the genetic origins of short stature.

Therapeutic optimization of growth hormone deficiency in children and adolescents

More than 40 years after the introduction of growth hormone (GH) treatment, many questions remain unanswered. Clearly, with the availability of rhGH and with current treatment protocols, treatment efficacy has improved. However, it still remains unclear whether current treatment protocols are the best possible. Before GH deficiency was recognized as a chronic disease, children only received treatment until normal adult height had been reached. However, it has recently been shown that not all GH-dependent body structures and functions normalize in parallel with height. Furthermore, in adolescents with GH deficiency, the interruption of GH substitution leads to severe hormone deficiency symptoms in adulthood. In the case of an adolescent who meets the biochemical criteria for GH deficiency in adulthood, but does not show alterations of metabolism, body structure, or emotional state, should GH treatment be started in adolescence, or only if and when the clinical syndrome becomes apparent? This is a difficult question to which there is not yet any clear answer, and we suggest that there is a need for further studies in this area. Furthermore, it will be necessary to re-evaluate the situation of patients who have completed their growth, and definitive conclusions will require controlled studies.