A rare and preventable aetiology of neurodevelopmental delay and epilepsy: familial glucocorticoid deficiency.

OBJECTIVES: Familial glucocorticoid deficiency (FGD) is a rare autosomal recessive disorder characterised by isolated glucocorticoid deficiency. Melanocortin receptor 2 (MC2R) mediates the functions of adrenocorticotropic hormone (ACTH) in the adrenal cortex. MC2R accessory protein (MRAP) is a transmembrane protein involved in the trafficking of MC2R to the cell surface. Mutations in MC2R and MRAP genes cause FGD type 1 and 2. In the present case series, we evaluate the clinical characteristics and long-term follow-up of six cases with FGD due to mutations in MC2R and MRAP. CASE PRESENTATION: Data of six cases with FGD (five with mutations in MC2R and one with a mutation in MRAP) who were being followed at our paediatric endocrine centre was evaluated. Diagnosis of FGD was considered in case of elevated ACTH and inappropriately low cortisol level, and exclusion of other aetiologies. The main presenting complaints were hyperpigmentation and hypoglycaemic convulsion in all cases. During a follow-up period of 26-115 months, one patient with homozygous 560delT mutation in MC2R, one female with G226R mutation in MC2R and one female with IVS3ds+1delG mutation in MRAP had a neurodevelopmental delay (NDD), while the other three patients had normal neurodevelopment. CONCLUSIONS: FGD patients due to MC2R and MRAP mutations with early diagnosis and compliance to the hydrocortisone therapy had normal neurodevelopment, while delay in diagnosis and poor compliance was associated with severe hypoglycaemic convulsions and subsequent complications NDD.

Genetic testing for familial hypercholesterolemia among survivors of acute coronary syndrome.

BACKGROUND: Familial hypercholesterolemia could be prevalent among patients with acute coronary syndrome. OBJECTIVE: To investigate both the frequency of causative mutations for familial hypercholesterolemia (FH) and the optimal selection of patients for genetic testing among patients with an acute coronary syndrome (ACS). METHODS: One hundred and sixteen patients with an ACS during 2009-2015 were identified through the SWEDEHEART registry. Patients who had either a high total cholesterol level ≥7 mmol L-1 combined with a triglyceride level ≤2.6 mmol L-1 , or were treated with lipid-lowering medication and had a total cholesterol level >4.9 mmol L-1 and a triglyceride level ≤2.6 mmol L-1 were included. Genetic testing was performed first with a regionally designed FH mutation panel (118 mutations), followed by testing with a commercially available FH genetic analysis (Progenika Biopharma). RESULTS: A total of 6.9% (8/116) patients had a FH-causative mutation, all in the LDL-receptor. Five patients were detected on the panel, and further testing of the remaining 111 patients detected an additional 3 FH-causative mutations. Baseline characteristics were similar in FH-positive and FH-negative patients with respect to age, gender, prior ACS and diabetes. Patients with a FH-causative mutation had higher Dutch Lipid Clinical Network (DLCN) score (5.5 (5.0-6.5) vs 3.0 (2.0-5.0), P < 0.001) and a higher low-density lipoprotein level (5.7 (4.7-6.5) vs 4.9 (3.5-5.4), P = 0.030). The Dutch Lipid Clinical Network (DLCN) score had a good discrimination with an area under the curve of 0.856 (95% CI 0.763-0.949). CONCLUSION: Genetic testing for FH should be considered in patients with ACS and high DLCN score.

[Uncommon neonatal case of hypoglycemia: ACTH resistance syndrome]. / Hypoglycémie néonatale sévère et récidivante sans perte de sel révélatrice d'un syndrome de résistance à l'ACTH.

Monitoring of blood glucose is usually reported to reduce the risk of hypoglycemia in term newborns with high risk factors and for prematurity in neonatal intensive care unit patients. Differential diagnosis has rarely been discussed. In the eutrophic term newborn, hypoglycemia remains rare and an etiological diagnosis must be made. Intensive management of neonatal hypoglycemia is required to prevent neurodevelopmental defects. Without evident cause or if hypoglycemia persists, a systematic review of possible causes should be made. We report isolated glucocorticoid deficiency diagnosed in an infant at 10 months of age. This boy had neonatal hypoglycemia and mild jaundice that had not been investigated. During his first 9 months of life, he presented frequent infections. At 10 months of age, febrile seizures occurred associated with shock, hypoglycemia, hyponatremia, mild hyperpigmentation, and coma. He was diagnosed with hypocortisolemia and elevated ACTH levels. Brain injury was revealed by MRI after resuscitation, with hypoxic-ischemic and hypoglycemic encephalopathy. The molecular studies demonstrated the presence of p.Asp107Asn and previously unreported frameshift p.Pro281GlnfsX9 MC2R gene mutations. A substitutive hormone therapy was provided and during a follow-up of 12 months no adrenal crisis was noted. We report an unusual case of familial glucocorticoid deficiency with severe neurological injury. This case demonstrates the importance of an appropriate etiological diagnosis in neonatal hypoglycemia.

Novel insight into etiology, diagnosis and management of primary adrenal insufficiency.

Primary adrenal insufficiency (PAI) is a rare condition in childhood which is either inherited (mostly) or acquired. It is characterized by glucocorticoid and maybe mineralocorticoid deficiency. The most common form in children is 21-hydroxylase deficiency, which belongs to the steroid biosynthetic defects causing PAI. Newer forms of complex defects of steroid biosynthesis are P450 oxidoreductase deficiency and (apparent) cortisone reductase deficiency. Other forms of PAI include metabolic disorders, autoimmune disorders and adrenal dysgenesis, e.g. the IMAGe syndrome, for which the underlying genetic defect has been recently identified. Newer work has also expanded the genetic causes underlying isolated, familial glucocorticoid deficiency (FGD). Mild mutations of CYP11A1 or StAR have been identified in patients with FGD. MCM4 mutations were found in a variant of FGD in an Irish travelling community manifesting with PAI, short stature, microcephaly and recurrent infections. Finally, mutations in genes involved in the detoxification of reactive oxygen species were identified in patients with unsolved FGD. Most mutations were found in the enzyme nicotinamide nucleotide transhydrogenase, which uses the mitochondrial proton pump gradient to produce NADPH. NADPH is essential in maintaining high levels of reduced forms of antioxidant enzymes for the reduction of hydrogen peroxide. Similarly, mutations in the gene for TXNRD2 involved in this system were found in FGD patients, suggesting that the adrenal cortex is particularly susceptible to oxidative stress.

A rare genetic disorder causing persistent severe neonatal hypoglycaemia the diagnostic workup.

We report a case of familial glucocorticoid deficiency (FGD), a rare genetic autosomal-recessive disorder with typical hyperpigmentation of the skin and mucous membranes, severe hypoglycaemia, occasionally leading to seizures and coma, feeding difficulties, failure to thrive and infections. A newborn child was admitted, on his second day of life, to our neonatal intensive care unit because of seizures and respiratory insufficiency. Hyperpigmentation was not evident due to his Senegalese origin. The clinical presentation led us to consider a wide range of diagnostic hypothesis. Laboratory findings brought us to the diagnosis of FGD that was confirmed by molecular analysis showing an MC2R:p.Y254C mutation previously reported as causative of type 1 FGD and two novel heterozygous non-synonymous single-nucleotide polymorphisms in exon 2 and 3 of melanocortin 2 receptor accessory protein-α, whose role in the disease is currently unknown. The importance of an early collection and storage of blood samples during hypoglycaemic event is emphasised.

A new model of care for familial hypercholesterolaemia: what is the role of cardiology?

Familial hypercholesterolaemia (FH) is a co-dominantly inherited disorder that causes marked elevation in plasma cholesterol and premature coronary heart disease. There are at least 45,000 people with FH in Australia and New Zealand, but most remain undiagnosed and undertreated. To bridge this gap in coronary prevention the FH Australasia Network has developed a model of care for FH. We present the executive summary, with a commentary contrasting the recommendations with other international guidelines and highlighting the role of the cardiologist.

Variable clinical spectrum of the most common inborn error of bile acid metabolism--3beta-hydroxy-Delta 5-C27-steroid dehydrogenase deficiency.

OBJECTIVE: We studied the clinical features of children with 3beta-hydroxy-Delta 5-C27-steroid dehydrogenase (3beta-HSDH) deficiency presenting to King's College and Great Ormond Street hospitals between 1989 and 2005. The diagnosis was made biochemically by detection of sulphated dihydroxycholenoic acids and trihydroxycholenoic acids in urine by fast atom bombardment mass spectrometry or electrospray ionisation tandem mass spectrophotometry and a plasma bile acid profile showing absent or low cholic and chenodeoxycholic acid levels and high concentrations of 3beta-7 alpha-dihydroxy-5-cholenoic acid and 3beta-7 alpha-12 alpha-trihydroxy-5-cholenoic acid. RESULTS: Eighteen children (12 male) with 3beta-HSDH deficiency were identified and diagnosed at a median age of 1.35 years (range 8 weeks-11 years). The presenting features included neonatal cholestasis (n = 11), rickets (n = 8, 1 of whom also had hypocalcaemic tetany, seizures, and normal liver biochemical markers), hepatomegaly (n = 7), pruritus (n = 3), and steatorrhoea and failure to thrive (n = 3). Ten children had low serum 25-OH vitamin D levels, of whom 8 also had low vitamin E and 6 had low vitamin A serum levels. Liver histology showed giant cell change and hepatocyte disarray in all with added features of cholestasis in 11, bridging fibrosis in 6, micronodular cirrhosis in 1, fatty change in 1, and active lobular and portal inflammation in 1. Five patients were treated with cholic acid and chenodeoxycholic acid (7 mg x kg(-1) x day(-1) of each), 7 with chenodeoxycholic acid only (7-18 mg x kg(-1) x day(-1)), and 1 with cholic acid (8 mg x kg(-1) x day(-1)) only. Repeated liver biopsies performed in 4 patients 6 months after starting replacement therapy showed improved histological changes. Three children died untreated before 5 years of age. After a median follow-up of 5.5 years (range 1-17 years) 12 out of 13 treated children have no clinical signs of liver disease or of fat-soluble vitamin deficiency. CONCLUSIONS: 3beta-HSDH deficiency is a rare inborn error of metabolism with diverse clinical features. Early replacement treatment leads to clinical and biochemical control and prevents chronic liver and bone disease, at least in the medium term.

Utilidad del equilibrio ácido-base y del ionograma en el tratamiento de la gastroenteritis aguda / Usefulness of acid-base and electrolyte balance in acute gastroenteritis

Introducción: La analítica sanguínea es solicitada frecuentemente para valorar a los pacientes con gastroenteritis aguda atendidos en urgencias, pero existen escasos estudios que determinen su utilidad real en el tratamiento de dichos pacientes. Objetivos: Nuestro estudio tiene los siguientes objetivos: a) determinar los motivos para que los pediatras soliciten una analítica en pacientes con gastroenteritis aguda; b) establecer el tipo y la frecuencia de las alteraciones analíticas encontradas en estos pacientes; c) valorar la capacidad de los pediatras para predecir alteraciones analíticas en niños con gastroenteritis aguda a partir de la anamnesis y la exploración física; d) evaluar la frecuencia con la que estas alteraciones analíticas producen cambios en el tratamiento inicial del paciente, y e) determinar si existe una asociación entre las variables clínicas y los resultados analíticos, y la duración de la estancia hospitalaria. Pacientes y métodos: Se incluyen en el estudio niños de edades comprendidas entre 3 meses y 18 años con síntomas de gastroenteritis aguda atendidos en el servicio de urgencias durante un período de 4 meses y para quienes se solicita analítica de sangre a criterio del pediatra. Resultados: De 4.172 niños atendidos por gastroenteritis aguda, se incluyeron en el estudio 163 pacientes a quienes se les practicó un estudio analítico. El motivo más frecuente para solicitar una analítica fue, en un 67,5 %, la sospecha clínica de deshidratación. Se objetivó una analítica alterada en el 77,9 % de los casos, destacando la acidosis metabólica (72,4 %). La sensibilidad para predecir una alteración analítica fue del 64,6 %, con una especificidad del 61,1 %. Los trastornos iónicos condicionaron un cambio en el tratamiento inicial del paciente en un 12,3 % de los casos. El 85,3 % de los pacientes requirió ingreso hospitalario; los valores de bicarbonato, sodio, urea y creatinina se correlacionaron con una estancia hospitalaria mayor o menor de 24 h. Conclusiones: La anamnesis y la exploración física presentan limitaciones para predecir la existencia de alteraciones hidroelectrolíticas clínicamente relevantes en pacientes sin signos clínicos de deshidratación o con deshidratación leve. Algunos parámetros analíticos presentan una buena correlación con el tiempo de permanencia hospitalaria del paciente (AU)

Introduction: Blood analysis blood is frequently requested for evaluating patients with acute gastroenteritis who come to our emergency department, but there are few studies that determine its real usefulness in the management of these patients. Objectives: a) To determine the reasons why paediatricians request laboratory tests in patients with acute gastroenteritis; b) to establish the type and frequency of laboratory abnormalities found in these patients; c) to evaluate the ability of paediatricians to predict laboratory abnormalities in children with acute gastroenteritis from the history and physical examination; d) to assess the frequency with which these laboratory findings change the initial management of the patient, and e) to determine whether there is an association between clinical and analytical results, and length of hospital stay. Patients and methods: Over a period of 4 months, children between 3 months and 18 years with symptomatic acute gastroenteritis seen in the emergency department and had laboratory tests requested by the paediatrician were included. Results: Of the 4,172 children seen with acute gastroenteritis, 163 patients who had laboratory tests done were included in the study. The most common reason for requests was clinical suspicion of dehydration in 67.5 %. Abnormal results were seen in 77.9 % of cases, mainly metabolic acidosis (72.4 %). The sensitivity analysis to predict an analytical abnormality was 64.6 % with a specificity of 61.1 %. Electrolyte disorders caused a change in the initial management in 12.3 % of patients, with 85.3 % of patients requiring hospital admission; bicarbonate, sodium, creatinine and urea values correlated with a hospital stay of more or less 24 hours. Conclusions: History and physical examination have limitations in predicting the presence of clinically significant electrolyte abnormalities in patients without clinical signs of dehydration or mild dehydration. Some laboratory tests correlate well with the length of patient stay in hospital (AU)

Defecto congénito de glucosilación tipo Ib. Experiencia en el tratamiento con manosa / Congenital disorder of glycosylation type 1b. Experience with mannose treatment

Los defectos congénitos de la glucosilación (CDG, por sus siglas en inglés) son enfermedades genéticas, en general multisistémicas, de herencia autosómica recesiva. Son causadas por defectos que afectan al ensamblaje, la transferencia o el procesamiento de los oligosacáridos de las proteínas u otros glucoconjugados. El CDG tipo Ib está causado por la deficiencia de la enzima citosólica fosfomanosa isomerasa (PMI), codificada por el gen MPI, que cataliza la interconversión de fructosa-6-P y manosa-6-P. Los síntomas son, fundamentalmente, gastrointestinales y hepáticos, y a diferencia de la mayoría de los pacientes con otros tipos de defectos congénitos de la glucosilación, no existe afectación neurológica. El tratamiento con manosa es muy eficaz. Describimos el primer caso de un paciente con CDG-Ib diagnosticado en España. La enfermedad se inició clínicamente a los 6 meses con hipoglucemia, fallo de medro e hipertransaminasemia; posteriormente el paciente desarrolló una enteropatía con atrofia vellositaria subtotal detectada en la biopsia. El paciente presentaba un porcentaje de transferrina deficiente en carbohidratos en el suero del 42 %, un patrón tipo 1 en el isoelectroenfoque de la transferrina sérica, una actividad PMI en fibroblastos del 16 % y las mutaciones R219Q y R56fs en el gen MPI. El tratamiento con manosa a dosis de 1 g/kg/día en 5 dosis resultó muy eficaz, y se normalizaron tanto los parámetros clínicos como los bioquímicos. El defecto congénito de la glucosilación Ib debería incluirse en el diagnóstico diferencial de hipoglucemias, hepatopatías, enteropatías y situaciones de hipercoagulabilidad, en ausencia de otras etiologías más comunes y, sobre todo, si se asocian varios de estos síntomas (AU)

Congenital disorders of glycosylation (CDG) are recessively inherited multisystemic disorders resulting from several genetic defects affecting the assembly, transfer or processing of oligosaccharides onto proteins and other glycoconjugates. CDG type Ib is due to a deficiency of phosphomannose isomerase (PMI) encoded by the MPI gene. PMI catalyzes the interconversion of fructose-6-P and mannose-6-P. The clinical phenotype is characterized by gastro-intestinal and hepatic symptoms. In contrast to most CDG patients, there is no neurological affectation. It's a mannose treatable disorder. We report the first recognised case of CDG Ib in Spain. He presented at 6 months with hypoglycaemia, failure to thrive and hypertransaminasaemia. He subsequently developed an enteropathy with subtotal villous atrophy on biopsy. The % CDT was very high and he presented with a type 1 pattern in transferrin isoelectric focusing. PMI activity in fibroblasts was very deficient. Mutations in MPI gene at R219Q and R56fs were found. Clinical and biochemical parameters normalised after treatment with mannose 1 g/kg/day in 5 doses. CDG Ib should be considered in patients with hypoglycaemia, liver disease, enteropathy and hypercoagulability, in the absence of other common causes, and particularly if some of them are combined (AU)

Los errores congénitos del metabolismo como enfermedades raras con un planteamiento global específico / Inborn errors of metabolism as rare diseases with a specific global situation

Las llamadas enfermedades congénitas del metabolismo(ECM) son consecuencia de alteraciones bioquímicasde origen génico que tienen como consecuencia la alteraciónde una proteína. Dependiendo de la función de estaproteína, ya sea como un enzima; como una hormona; comoun receptor-transportador de membrana celular; o formandoparte de una organela celular (lisosoma, peroxisoma)surgen diferentes grupos de enfermedades, lo cual originala característica más destacada de los errores innatos delmetabolismo (EIM) que es su gran heterogeneidad clínica.La mayoría de estas enfermedades son autosómico-recesivas,con un número limitado de portadores asintomáticos,pero también las hay regidas por una herencia de carácterautonómica dominante o ligada al cromosoma X. Uno a uno,realmente los ECM son muy poco frecuentes pero en suconjunto los ECM (de los cuales hay descritos en el momentoactual más de 500) pueden afectar al 1/500 recién nacidos.Una característica común a muchos ECM es la posibilidadde tratamiento dietético y el tratamiento con sustituciónenzimática.Desde el punto de vista práctico es útil considerar suclasificacion atendiendo al momento de inicio de los síntomasy a la forma de presentación de las manifestaciones clínicas.Desde esta perspectiva y con fines fundamentalmentedidácticos se deben considerar los siguientes grupos:ECM del metabolismo intermediario, (tipo intoxicación, ytipo déficit energético). Errores congénitos del metabolismode las organelas celulares, y EMCM complejos por alteraciónde ciclos y otros. Se presentan de forma resumidalos aspectos clínicos, diagnósticos y terapéuticos de unaenfermedad de cada tipo de las descritas anteriormente:hiperfenilalaninemias, deficiencias de la fosforilación oxidativamitocondrial (OXPHOS) y enfermedades lisosomales

So-called congenital metabolic diseases (CMD) are aconsequence of biochemical alterations originating in thegenes that result in the alteration of a protein. Dependingon this protein’s function - whether as an enzyme, a hormone,a receiver-transporter of a cellular membrane orforming part of a cellular organelle (lysosome, peroxysome)– different groups of diseases emerge, which cause the mostoutstanding characteristic of inborn errors of metabolism(IEM): their clinical heterogeneity. The majority of these diseasesare autosomal recessive, with a limited number ofasymptomatic carriers, but there are also those ruled by anautonomous, dominant character inheritance or linked tothe X chromosome. Taken individually, CMDs are highlyinfrequent, but taken as a whole CMDs (of which over 500have been described to date) can affect 1/500 of the newborn.A common characteristic of many CMDs is the possibilityof dietary treatment and treatment with enzymaticreplacement.For essentially didactic purposes the following groupsshould be considered: CMDs of the intermediary metabolism(whose types are intoxication and energy deficit),CMDs of cellular organelles, complex CMDs due to cyclealterations and others. A summary is presented of the clinical,diagnostic and therapeutic aspects of one disease ofeach type of those previously described: hyperphenylalaninemias,deficiencies of the mitochondrial oxidative phosphorilation(OXPHOS) and lysosomal storage diseases

Stomatocytic haemolysis and macrothrombocytopenia (Mediterranean stomatocytosis/macrothrombocytopenia) is the haematological presentation of phytosterolaemia.

Phytosterolaemia (sitosterolaemia) is a recessively inherited metabolic condition in which the absorption of both cholesterol and plant-derived cholesterol-like molecules at the gut is unselective and unrestricted. In haematology, Mediterranean stomatocytosis or Mediterranean macrothrombocytopenia is a poorly understood haematological condition that combines stomatocytic haemolysis with the presence of very large platelets. Five pedigrees showing this haematology were identified. Gas chromatography mass spectrometry (GC-MS) showed that all of the patients with this highly specific haematology had grossly elevated levels of phytosterols in the blood, diagnostic of phytosterolaemia. All showed mutations in the ABCG5 and ABCG8 previously linked to phytosterolaemia. Three pedigrees showed five new mutations, while two pedigrees showed the common W361X mutation in ABCG8. We draw the following four conclusions: (i) that Mediterranean stomatocytosis/macrothrombocytopenia is caused by an excess of phytosterols in the blood; (ii) that phytosterolaemia, which does not respond to standard statin treatment, can be diagnosed via the distinctive haematology described here, even when the cholesterol is normal; (iii) that phytosterolaemia should be considered in the differential diagnosis of all patients with large platelets; and (iv) that the platelet size should be noted in patients with hypercholesterolaemia.

Primary empty sella.

CONTEXT: The term primary empty sella (PES) refers to a number of endocrine and/or neurological disturbances that may be caused by the herniation of subarachnoid space within the sella. SETTING: The records of all patients with a diagnosis of empty sella between 1985 and 2002 seen at the Catholic University of Rome and University of Brescia were examined retrospectively. PATIENTS: We have observed 171 female and 42 male patients affected by PES (over 4:1 sex ratio). The mean age at diagnosis in our subjects was 51.8 +/- 2.1 yr. Mean body mass index was 27.3 +/- 3.5 kg/m2. MAIN OUTCOME MEASURE: All the patients have been analyzed first either with sellar computed tomography scan or magnetic resonance imaging. All patients underwent neurological, ophthalmological, and baseline endocrine evaluation (appropriate stimulation tests were performed when hypopituitarism was suspected). RESULTS: In the overall population, 40 of 213 patients had documented endocrine abnormalities, specifically 31 females and nine males. Twenty-two patients (10.3% of total patients; 18 women, 10.5% of all women, with a mean age of 38.6 +/- 1.1 yr and four males, with a mean age 46.5 +/- 3.52 yr) presented with hyperprolactinemia. Global anterior hypopituitarism was confirmed in nine patients. Eight patients presented an isolated GH deficiency. One hundred thirty-eight of our patients presented a so-called partial empty sella at computed tomography scan/magnetic resonance imaging, and 75 had total PES. CONCLUSIONS: PES may be associated with variable clinical conditions ranging from mild endocrine disturbances to severe intracranial hypertension and rhinorrhea. The need for treatment of hyperprolactinemia as well as for replacement hormone therapy must be assessed in PES. Symptomatic intracranial hypertension makes cerebrospinal fluid shunting procedures necessary.

Hypertension in a patient with aldosterone deficiency.

OBJECTIVE: To describe a patient with aldosterone synthase deficiency, who presented with failure to thrive, hypovolemic hyponatremia, and the unexpected finding of hypertension. METHODS: We present a case report, review the related literature, and outline a possible mechanism for the concomitant occurrence of high blood pressure and hyponatremia in this patient. RESULTS: A 5-month-old infant with unambiguous female genitalia was admitted to our hospital with failure to thrive and hyponatremia. Her blood pressure was 115/88 mm Hg (>95% for age). The serum sodium concentration was 123 mEq/L (normal for age, >130), and the potassium level was 5.3 mEq/L (normal, 3.5 to 5.3). A direct renin measurement by immunochemiluminescence assay was 11,400 microU/mL (normal, <5), and the aldosterone level was 4 ng/dL (normal, 2 to 70). These findings indicated a diagnosis of aldosterone synthase deficiency. Treatment with fludrocortisone and sodium chloride was begun, but the hypertension worsened. Therapy with an angiotensin-converting enzyme inhibitor was transiently required. CONCLUSION: Angiotensin II, a potent vasoconstrictor, is an intermediate in the renin-angiotensin system. We believe that this protein was the cause of the hypertension in the setting of aldosterone deficiency in our patient.

Cardiovascular disease and risk factors: the role of growth hormone.

Clinical studies in patients with acromegaly have shown that growth hormone (GH) exerts both short- and long-term effects on the structure and function of the heart. Moreover, chronic growth hormone deficiency (GHD) has been associated with impaired cardiac performance, low heart rate and impaired left ventricular systolic function. Exercise capacity in patients with GHD is significantly reduced and in some severely affected individuals, dilated cardiomyopathy and heart failure has been reported. GHD has also been associated with a number of risk factors for cardiovascular disease. Altered lipoprotein metabolism and elevated fibrinogen and plasminogen activator inhibitor-1 activity are associated with GHD, and the risk of hypertension is increased in GH-deficient men. Subcutaneous and intra-abdominal fat mass have also been found to be abnormally high in these patients. These effects may contribute to an increased risk of death from cardiovascular disease. GH is therefore an important factor in the development and function of the cardiovascular system. In this paper, the effects of GH on the physiological mechanisms of the cardiovascular system are discussed, including the effect of GHD on cardiovascular disease risk. We will also discuss the effects of long-term GH replacement therapy in this patient population.

Novel insights into the aetiology and pathogenesis of hypopituitarism.

Recent advances in our knowledge of pituitary development, acquired mainly from animal models, have enhanced our understanding of the aetiology of isolated growth hormone deficiency (IGHD) and combined pituitary hormone deficiency (CPHD), as well as several syndromic forms of growth hormone deficiency (GHD). A number of developmental genes known to be important for organ commitment and cell differentiation and proliferation (HESX1, LHX3, LHX4, PROP1 and PIT1) have been implicated in CPHD with or without other syndromic features. Phenotypes associated with these genetic mutations and their inheritance may be highly variable. Functional analyses of these mutations reveal valuable insights into the function of the proteins and hence into the effect of these mutations on phenotype. Novel insights have been gained into the mechanisms whereby these genes are associated with particular phenotypes as a result of murine transgenesis, e.g. type II autosomal dominant GHD. Mutations within known genes account for a small proportion of cases of IGHD and CPHD, suggesting the role of other as yet unidentified genetic and environmental factors. Hence, genetic testing will in the future have a greater role to play in understanding the mechanisms leading to particular hypopituitary phenotypes and also in predicting the evolution of these disorders. There is, however, no substitute for careful delineation of the phenotype prior to undertaking genetic studies.

Growth hormone deficiency in patients with sickle cell disease and growth failure.

BACKGROUND: Growth disorders are common in children with sickle cell disease (SCD). The etiology for growth disturbances in this population appears to be multifactorial. Recent evidence suggests abnormalities in the growth hormone (GH)/insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3) axis may play a role. OBJECTIVE: To measure GH levels through provocative stimulation in a group of patients with SCD with growth failure, and to evaluate response to treatment. PATIENTS AND METHODS: Growth records were reviewed of 79 children with sickle cell hemoglobinopathies to identify children with growth failure. GH levels were measured in patients with SCD with and without growth failure using arginine and L-Dopa as provocative stimulation tests. Treatment with GH was offered to GH-deficient children with SCD and these patients were followed longitudinally over 5 years. RESULTS: Of the 79 patients, 13 (16.5%, all SS) had heights less than -2 SD below the mean or a growth velocity < -2 SD below the mean for age. Seven of the 13 children with growth failure participated in this study. Five patients received GH for 3 or more years and demonstrated significant improvement in their height SDS. One of the two who declined treatment was lost to follow-up and the other had significant worsening of height SDS score. CONCLUSION: GH deficiency may be associated with growth failure in some patients with SCD. These patients may benefit from treatment with GH.