Neonatal cardiac hypertrophy: the role of hyperinsulinism-a review of literature.

Hypertrophic cardiomyopathy (HCM) in neonates is a rare and heterogeneous disorder which is characterized by hypertrophy of heart with histological and functional disruption of the myocardial structure/composition. The prognosis of HCM depends on the underlying diagnosis. In this review, we emphasize the importance to consider hyperinsulinism in the differential diagnosis of HCM, as hyperinsulinism is widely associated with cardiac hypertrophy (CH) which cannot be distinguished from HCM on echocardiographic examination. We supply an overview of the incidence and treatment strategies of neonatal CH in a broad spectrum of hyperinsulinemic diseases. Reviewing the literature, we found that CH is reported in 13 to 44% of infants of diabetic mothers, in approximately 40% of infants with congenital hyperinsulinism, in 61% of infants with leprechaunism and in 48 to 61% of the patients with congenital generalized lipodystrophy. The correct diagnosis is of importance since there is a large variation in prognoses and there are various strategies to treat CH in hyperinsulinemic diseases.Conclusion: The relationship between CH and hyperinsulism has implications for clinical practice as it might help to establish the correct diagnosis in neonates with cardiac hypertrophy which has both prognostic and therapeutic consequences. In addition, CH should be recognized as a potential comorbidity which might necessitate treatment in all neonates with known hyperinsulinism.What is Known:• Hyperinsulinism is currently not acknowledged as a cause of hypertrophic cardiomyopathy (HCM) in textbooks and recent Pediatric Cardiomyopathy Registry publications.What is New:• This article presents an overview of the literature of hyperinsulinism in neonates and infants showing that hyperinsulinism is associated with cardiac hypertrophy (CH) in a broad range of hyperinsulinemic diseases.• As CH cannot be distinguished from HCM on echocardiographic examination, we emphasize the importance to consider hyperinsulinism in the differential diagnosis of HCM/CH as establishing the correct diagnosis has both prognostic and therapeutic consequences.

Hypertrophic cardiomyopathy in Donohue syndrome.

We report the case of a patient with Donohue syndrome who died of heart failure due to obstructive hypertrophic cardiomyopathy. A literature survey revealed that hypertrophic cardiomyopathy was present in 30% of these patients and was often fatal. Therefore, every patient with Donohue syndrome should be screened for hypertrophic cardiomyopathy.

Clinical heterogeneity and diagnostic delay of autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autosomal recessive organ-specific autoimmune disorder that is characterized by a variable combination of (i) chronic mucocutaneous candidiasis, (ii) polyendocrinopathy and/or hepatitis and (iii) dystrophy of the dental enamel and nails. We analyzed the AIRE (autoimmune regulator) gene in subjects who presented any symptom that has been associated with APECED, including candidiasis and autoimmune endocrinopathy. We observed that 83.3% of patients presented at least two of the three typical manifestations of APECED, while the remaining 16.7% of patients showed other signs of the disease. Analysis of the genetic diagnosis of these subjects revealed that a considerable delay occurs in the majority of patients between the appearance of symptoms and the diagnosis. Overall, the mean diagnostic delay in our patients was 10.2 years. These results suggest that molecular analysis of AIRE should be performed in patients with relapsing mucocutaneous candidiasis for early identification of APECED.

Characterization of a novel loss-of-function mutation of PAX8 associated with congenital hypothyroidism.

BACKGROUND: Congenital hypothyroidism (CH) is a common endocrine disease that occurs in about 1:3000 newborns. In 80-85% of the cases, CH is presumably secondary to thyroid dysgenesis (TD), a defect in the organogenesis of the gland leading to an ectopic (30-45%), absent (agenesis, 35-40%) or hypoplastic (5%) thyroid gland. The pathogenesis of TD is still largely unknown. Most cases of TD are sporadic, although familial occurrences have occasionally been described. Recently, mutations in the PAX8 transcription factor have been identified in patients with TD. OBJECTIVE: Our aim was to identify and functionally characterize novel PAX8 mutations with autosomal dominant transmission responsible for TD. DESIGN: The PAX8 gene was sequenced in a mother and child both suffering from congenital hypothyroidism (CH) because of thyroid hypoplasia. Subsequently, expression vectors encoding the mutated PAX8 were generated, and the effects of the mutation on both the DNA-binding capability and the transcriptional activity were evaluated. RESULTS: PAX8 gene sequencing revealed a heterozygous mutation that consists of the substitution of a histidine residue with a glutamine at position 55 of the PAX8 protein (H55Q). When tested in cotransfection experiments with a thyroglobulin promoter reporter construct, the mutant protein turned out to be still able to bind DNA in Electrophoretic Mobility Shift Assay assays but transcriptionally inactive. CONCLUSIONS: Our findings confirm the important role of PAX8 in normal thyroid development and support the evidence that in humans haploinsufficiency of PAX8 is associated with TD.

Bone mineral density in children with moderate to severe atopic dermatitis.

BACKGROUND: Low bone mineral density (BMD) has been reported in 30.4% of adult patients with atopic dermatitis (AD). OBJECTIVE: The aim of this study was to determine the prevalence of low BMD in children with moderate to severe AD and to investigate the relation between BMD and corticosteroid and cyclosporine therapy. METHODS: Lumbar spine BMD was measured by dual-energy X-ray absorptiometry in 60 children (age 5-16 years) with moderate to severe AD. BMD (in g/cm(2)) was expressed in Z-scores, the number of SD above or below the mean value of an age- and sex-matched reference population. In children, low BMD was defined as a Z-score less than -2. Information on lifestyle parameters and bone fractures were collected by use of a standardized questionnaire. The cumulative dose of corticosteroids and cyclosporine therapy was calculated for the previous 5-year period. RESULTS: Three patients (5%) had low BMD; one patient (1.7%) had osteoporosis. The observed prevalence of low BMD in this study (6.7%; 95% confidence interval 1.8%-16.2%) does not differ from the expected prevalence of low BMD in the general population (P = .06). Overall, use of topical corticosteroids in the previous 5 years was not associated with a decrease in BMD (Z-score). When children received additional systemic treatment (oral corticosteroids and/or cyclosporine) in the previous 5 years, BMD decreased, although the decrease was not statistically significant. Correction for lifestyle parameters did not change these associations. LIMITATIONS: The number of patients studied was limited. The cumulative dose of corticosteroids and cyclosporine therapy was only registered for the previous 5 years, and relatively low amounts of topical corticosteroids were used. The definition of low BMD differs between adults (Z-score < -1) and children (Z-score < -2). Because there is no Dutch BMD reference population for children, normative BMD references were obtained from a different population (US children). CONCLUSIONS: Low BMD did not occur more frequently in this population of children with moderate to severe AD compared with the general population. Use of topical corticosteroids in the previous 5 years was not associated with a decrease in BMD.

Unmasking of a hemizygous WFS1 gene mutation by a chromosome 4p deletion of 8.3 Mb in a patient with Wolf-Hirschhorn syndrome.

The Wolf-Hirschhorn syndrome (WHS (MIM 194190)), which is characterized by growth delay, mental retardation, epilepsy, facial dysmorphisms, and midline fusion defects, shows extensive phenotypic variability. Several of the proposed mutational and epigenetic mechanisms in this and other chromosomal deletion syndromes fail to explain the observed phenotypic variability. To explain the complex phenotype of a patient with WHS and features reminiscent of Wolfram syndrome (WFS (MIM 222300)), we performed extensive clinical evaluation and classical and molecular cytogenetic (GTG banding, FISH and array-CGH) and WFS1 gene mutation analyses. We detected an 8.3 Mb terminal deletion and an adjacent 2.6 Mb inverted duplication in the short arm of chromosome 4, which encompasses a gene associated with WFS (WFS1). In addition, a nonsense mutation in exon 8 of the WFS1 gene was found on the structurally normal chromosome 4. The combination of the 4p deletion with the WFS1 point mutation explains the complex phenotype presented by our patient. This case further illustrates that unmasking of hemizygous recessive mutations by chromosomal deletions represents an additional explanation for the phenotypic variability observed in chromosomal deletion disorders.

Congenital isolated adrenocorticotropin deficiency: an underestimated cause of neonatal death, explained by TPIT gene mutations.

Tpit is a T box transcription factor important for terminal differentiation of pituitary proopiomelanocortin-expressing cells. We demonstrated that human and mouse mutations of the TPIT gene cause a neonatal-onset form of congenital isolated ACTH deficiency (IAD). In the absence of glucocorticoid replacement, IAD can lead to neonatal death by acute adrenal insufficiency. This clinical entity was not previously well characterized because of the small number of published cases. Since identification of the first TPIT mutations, we have enlarged our series of neonatal IAD patients to 27 patients from 21 unrelated families. We found TPIT mutations in 17 of 27 patients. We identified 10 different TPIT mutations, with one mutation found in five unrelated families. All patients appeared to be homozygous or compound heterozygous for TPIT mutations, and their unaffected parents are heterozygous carriers, confirming a recessive mode of transmission. We compared the clinical and biological phenotype of the 17 IAD patients carrying a TPIT mutation with the 10 IAD patients with normal TPIT-coding sequences. This series of neonatal IAD patients revealed a highly homogeneous clinical presentation, suggesting that this disease may be an underestimated cause of neonatal death. Identification of TPIT gene mutations as the principal molecular cause of neonatal IAD permits prenatal diagnosis for families at risk for the purpose of early glucocorticoid replacement therapy.

A Patient with Congenital Generalized Lipodystrophy Due To a Novel Mutation in BSCL2: Indications for Secondary Mitochondrial Dysfunction.

BACKGROUND: Congenital generalized lipodystrophy (CGL) results from mutations in AGPAT2, encoding 1-acyl-glycerol-3-phosphate-acyltransferase 2 (CGL1; MIM 608594), BSCL2, encoding seipin (CGL2; MIM 269700), CAV1, encoding caveolin1 (CGL3; MIM 612526) or PTRF, encoding polymerase I and transcript release factor (CGL4; MIM 613327). This study aims to investigate the genotype/phenotype relationship and search for a possible pathogenic mechanism in a patient with CGL. DESIGN: Case report. PATIENTS AND SETTING: A 7-day-old child of consanguineous Turkish parents presented with a generalized loss of subcutaneous fat. He had a strikingly enlarged liver, high serum triglycerides, and hyperglycaemia, suggestive for CGL. RESULTS: A novel homozygous mutation in the acceptor splice site of exon 5 of the BSCL2 gene was found in the genome of the proband. This mutation causes a complex RNA splicing defect and results in two different aberrant seipin proteins, which were normally expressed and localized to the endoplasmic reticulum like wild type protein. Analysis of the patient's urine showed intermittent elevations of citric acid intermediates and persistently high concentrations of ethylmalonic acid, suggestive of a disturbance of the mitochondrial respiratory chain. CONCLUSION: Here we report abnormal urinary organic acid levels, indicative of mitochondrial dysfunction, in a patient with CGL resulting from a novel mutation in BSCL2. Our findings suggest for the first time an association between CGL and secondary mitochondrial dysfunction.

Cardiovascular and metabolic outcome in 6-8 year old offspring of women with type 1 diabetes with near-optimal glycaemic control during pregnancy.

BACKGROUND: High maternal glucose concentrations during diabetic pregnancy may lead to health problems in the offspring later in life. We showed in a previous nationwide study on pregnancy outcome in type 1 diabetic women that prepregnancy care was good and a near-optimal glycaemic control during pregnancy was achieved (mean HbA1c 6.2%). AIMS: We investigated to what extent current care and treatment of pregnant women with type 1 diabetes were related to cardiovascular and metabolic disturbances in the offspring at school age. Additionally, we studied the influence of level of maternal glycaemic control, preterm birth and neonatal macrosomia (birth weight>p 90). STUDY DESIGN: Observational cohort study. SUBJECTS: 6-8 year old offspring of women with type 1 diabetes (ODM, n=213) and a control group of children of non-diabetic women (n=79). OUTCOME MEASURES: BMI, blood pressure, parameters of fasting glucose regulation and lipid metabolism, components of the metabolic syndrome (overweight, hypertension, impaired fasting glucose, dyslipidaemia). RESULTS: Parameters of fasting glucose regulation and lipid metabolism and the frequency of components of the metabolic syndrome did not significantly differ between ODM and controls. Systolic blood pressure was slightly higher in ODM. The influence of level of maternal glycaemic control, preterm birth and neonatal macrosomia on outcome in ODM was limited. CONCLUSIONS: Current care and treatment of pregnant women with type 1 diabetes result in cardiovascular and metabolic outcome in the offspring at 6-8 years of age that is comparable to that in children of non-diabetic women. Further follow-up should substantiate these results at later age.

Risk factors for childhood overweight in offspring of type 1 diabetic women with adequate glycemic control during pregnancy: Nationwide follow-up study in the Netherlands.

OBJECTIVE: Pregnancy in type 1 diabetic women remains a high-risk situation for both mother and child. In this study, we investigated long-term effects on body composition, prevalence of overweight, and insulin resistance in children of type 1 diabetic women who had had adequate glycemic control during pregnancy (mean A1C 6.2%), and we related their outcome to perinatal factors, including macrosomia (birth weight >90th percentile). RESEARCH DESIGN AND METHODS: Anthropometric measurements were performed at 6-8 years of age in 213 offspring of type 1 diabetic mothers who participated in a previous nationwide study. Homeostasis model assessment of insulin resistance (HOMA-IR) was determined from a fasting blood sample in 155 of these children. In addition, we studied BMI standard deviation score (SDS) growth trajectories. Results were compared with national reference data. RESULTS: The prevalence of overweight in the study population was not different from that in the reference population. However, children who were born macrosomic showed twice as much overweight as nonmacrosomic children. Macrosomia and maternal overweight were independent predictors of childhood overweight. Overweight children showed an increase in BMI SDS starting already after 6 months of age and had a significantly increased HOMA-IR. CONCLUSIONS: In type 1 diabetic women with adequate glycemic control during pregnancy, long-term effects on body composition and overweight in their offspring at school age are limited and related mainly to macrosomia at birth. Possible targets for prevention of childhood overweight are fetal macrosomia, maternal overweight, and an increase in BMI SDS during the first years of life.

Laparoscopic diagnosis and cure of hyperinsulinism in two cases of focal adenomatous hyperplasia in infancy.

Persistent hyperinsulinemic hypoglycemia of infancy or congenital hyperinsulinism of the neonate is a rare condition that may cause severe neurologic damage if the disease is unrecognized or inadequately treated. Current treatment aims to restore normal blood glucose levels by providing a carbohydrate-enriched diet and drugs that inhibit insulin secretion. If medical treatment fails, then surgery is required. Because congenital hyperinsulinism may be caused either by diffuse involvement of pancreatic beta-cells or by a focal cluster of abnormal beta-cells, the extent of pancreatectomy varies. We report on 2 patients with a focal form of the disease for whom diagnosis was made with laparoscopy. Laparoscopic enucleation of the lesion was curative.

Human and mouse TPIT gene mutations cause early onset pituitary ACTH deficiency.

Tpit is a highly cell-restricted transcription factor that is required for expression of the pro-opiomelanocortin (POMC) gene and for terminal differentiation of the pituitary corticotroph lineage. Its exclusive expression in pituitary POMC-expressing cells has suggested that its mutation may cause isolated deficiency of pituitary adrenocorticotropin (ACTH). We now show that Tpit-deficient mice constitute a model of isolated ACTH deficiency (IAD) that is very similar to human IAD patients carrying TPIT gene mutations. Through genetic analysis of a panel of IAD patients, we show that TPIT gene mutations are associated at high frequency with early onset IAD, but not with juvenile forms of this deficiency. We identified seven different TPIT mutations, including nonsense, missense, point deletion, and a genomic deletion. This work defines congenital early onset IAD as a relatively homogeneous clinical entity caused by recessive transmission of loss-of-function mutations in the TPIT gene.