Bone Characteristics and Their Determinants in Adolescents and Young Adults with Early-Onset Severe Obesity.

Childhood obesity is associated with compromised bone health. We studied bone characteristics and their determinants in obese young adults. The study included 68 subjects with early-onset severe obesity and 73 normal-weight controls. Data on physical activity (PA), diet and smoking were collected. Bone characteristics were measured using peripheral QCT. The obese and control subjects were similar in age (mean 19.6 ± 2.6 years) and height but BMIs differed (39.7 and 22.6 kg/m(2)). A clustering of unhealthy lifestyles was marked: Obese subjects reported less supervised PA in childhood, adolescence and currently (p < 0.03) and were more likely to smoke (p = 0.005), and had a lower healthy eating index (HEI) (p = 0.007) but similar alcohol consumption compared with controls. In obese women, all crude bone characteristics were higher than in controls; in men, the differences were smaller. Associations of lifestyle factors with bone characteristics were tested using partial correlations. Independently of BMI, supervised PA in adolescence and alcohol consumption were related positively to bone characteristics in both groups. HEI associated positively with bone characteristics only in controls, while smoking was a positive determinant of bone characteristics only in obese subjects. The multivariate model showed that the contribution of lifestyle factors to bone characteristics was minimal compared with BMI. Early-onset obesity is accompanied by poor dietary quality, sedentary lifestyle, and more frequent smoking, but the overall contribution of these lifestyle factors to bone strength is limited. Bone strength is more likely to be compromised in men and in unloaded bone sites in subjects with early-onset severe obesity. The impact of obesity-related endocrine changes on bone characteristics need to be evaluated in future studies.

Cardiac dysfunction in children with mulibrey nanism.

Mulibrey nanism is an autosomal recessive disease with severe growth failure and multiple organ involvement. Heart manifestations include constrictive pericarditis and restrictive cardiomyopathy. The purpose of this study was to evaluate left ventricular (LV) diastolic and systolic function in children with mulibrey nanism utilizing two- and three- dimensional (2-D and 3-D) echocardiography and measurement of serum levels of natriuretic peptides. Of the 30 children diagnosed with mulibrey nanism in Finland, 26 participated. The control group comprised 26 children. In 2-D echocardiography, the interventricular septum and LV posterior wall were thicker in patients. The left atrium/aorta ratio measured a median 1.8 (range, 1.4-2.5) in patients and 1.3 (range, 1.0-1.7) in controls (p < 0.001). Patients differed from controls in several indices of diastolic LV function. In 3-D echocardiography, LV end diastolic volume measured a median of 51.9 ml/m(2) (range, 33.3-73.4) in patients and 59.7 ml/m(2) (range, 37.6-87.6) in controls (p = 0.040), and serum levels of N-terminal proatriopeptide and N-terminal pro-brain natriuretic peptide measured, respectively, a median of 0.54 nmol/L (range, 0.04-4.7) and 289 ng/L (range, 18-9170) in patients and 0.28 nmol/L (range, 0.09-0.72; p < 0.001) and 54 ng/L (range, 26-139; p < 0.001) in controls. They correlated with several indices of diastolic LV function. In a significant proportion of children with mulibrey nanism, myocardial function is impaired. Significant correlations appeared between indices of LV function, size of the left atrium, and levels of natriuretic peptides, showing that measurement of serum levels of natriuretic peptides is a useful follow-up method despite its dependence on loading conditions.

Global analysis of uniparental disomy using high density genotyping arrays.

BACKGROUND: Uniparental disomy (UPD), the inheritance of both copies of a chromosome from a single parent, has been identified as the cause for congenital disorders such as Silver-Russell, Prader-Willi, and Angelman syndromes. Detection of UPD has largely been performed through labour intensive screening of DNA from patients and their parents, using microsatellite markers. METHODS: We applied high density single nucleotide polymorphism (SNP) microarrays to diagnose whole chromosome and segmental UPD and to study the occurrence of continuous or interspersed heterodisomic and isodisomic regions in six patients with Silver-Russell syndrome patients who had maternal UPD for chromosome 7 (matUPD7). RESULTS: We have devised a new high precision and high-throughput computational method to confirm UPD and to localise segments where transitions of UPD status occur. Our method reliably confirmed and mapped the matUPD7 regions in all patients in our study. CONCLUSION: Our results suggest that high density SNP arrays can be reliably used for rapid and efficient diagnosis of both segmental and whole chromosome UPD across the entire genome.

Mulibrey nanism: clinical features and diagnostic criteria.

Mulibrey nanism (MUL) is an autosomal recessive disease caused by mutations in the TRIM37 gene encoding the peroxisomal TRIM37 protein of unknown function. In this work, we analysed the clinical characteristics of 85 Finnish patients with MUL, most of whom were homozygous for the Finn major mutation of TRIM37. The patients' hospital records from birth to the time of the diagnosis at age 0.02-52 years (median 2.1 years) were retrospectively analysed. All except four of the patients (95%) had a prenatal onset growth failure without postnatal catch up growth. The mean length standard deviation score (SDS) was -3.1 and -4.0 at birth and at diagnosis, respectively. In infancy, feeding difficulties, and respiratory tract infections were the most common problems. Congestive heart failure and pericardial constriction were diagnosed during infancy in 12% and 6% of the patients, respectively. At the time of the diagnosis, characteristic craniofacial features of scaphocephaly, facial triangularity, high and broad forehead, and low nasal bridge were evident in over 90% of the patients. In addition, practically all patients were gracile and had thin extremities. Other findings included a peculiar high-pitched voice (96%), yellowish dots in ocular fundi (79%), cutaneous naevi flammei (65%), hepatomegaly (45%), and fibrous dysplasia of long bones (25%). Mild muscular hypotonicity (68%) was the only neurological abnormality. The clinical features of the Finnish patients with MUL formed a distinct entity. The most consistent findings were growth failure and characteristic craniofacial features. However, organ manifestations varied considerably in early childhood. Based on these findings, we propose new diagnostic criteria for MUL.

Maternal and paternal chromosomes 7 show differential methylation of many genes in lymphoblast DNA.

Genomic imprinting, the differential expression of paternal and maternal alleles, involves many chromosomal regions and plays a role in development and growth. Differential methylation of maternal and paternal alleles is a hallmark of imprinted genes, and thus methylation assays are widely used to support the identification of novel imprinted genes. Either blood or lymphoblast DNAs are most often used in these assays, even though methylation levels may change in cell culture. We undertook a systematic survey of parent-of-origin-specific methylation of chromosome 7 genes and ESTs by comparing DNA samples from cases of maternal and paternal uniparental disomy for chromosome 7 using DNA from fresh blood and lymphoblast cell lines. Our results revealed that up to 41% of genes and ESTs show parent-of-origin-specific methylation differences in lymphoblast DNA after only a short time in culture, whereas methylation differences were not seen in blood DNA. The methylation changes occurred most commonly on paternal chromosome 7, whereas alterations on maternal chromosome 7 were more infrequent and weaker. These findings indicate that methylation patterns may change significantly during cell culture in a parent-of-origin-dependent manner and suggest that methylation is maintained differently on maternal and paternal chromosomes 7.

A narrow segment of maternal uniparental disomy of chromosome 7q31-qter in Silver-Russell syndrome delimits a candidate gene region.

Maternal uniparental disomy of chromosome 7 (matUPD7), the inheritance of both chromosomes from only the mother, is observed in approximately 10% of patients with Silver-Russell syndrome (SRS). It has been suggested that at least one imprinted gene that regulates growth and development resides on human chromosome 7. To date, three imprinted genes-PEG1/MEST, gamma2-COP, and GRB10-have been identified on chromosome 7, but their role in the etiology of SRS remains uncertain. In a systematic screening with microsatellite markers, for matUPD7 cases among patients with SRS, we identified a patient who had a small segment of matUPD7 and biparental inheritance of the remainder of chromosome 7. Such a pattern may be explained by somatic recombination in the zygote. The matUPD7 segment at 7q31-qter extends for 35 Mb and includes the imprinted gene cluster of PEG1/MEST and gamma2-COP at 7q32. GRB10 at 7p11.2-p12 is located within a region of biparental inheritance. Although partial UPD has previously been reported for chromosomes 6, 11, 14, and 15, this is the first report of a patient with SRS who has segmental matUPD7. Our findings delimit a candidate imprinted region sufficient to cause SRS.

Impaired glucose tolerance and dyslipidaemia as late effects after bone-marrow transplantation in childhood.

BACKGROUND: This follow-up study aimed to assess the frequency of late effects on glucose and lipid metabolism after bone-marrow transplantation in childhood. METHODS: 23 long-term survivors (median age 20 years) were studied 3-18 years after bone-marrow transplantation and compared with 23 healthy controls matched for age and sex and with 13 patients in remission from leukaemia. FINDINGS: 12 (52%) of the 23 bone-marrow transplantation patients had insulin resistance, including impaired glucose tolerance in six and type 2 diabetes in four. The core signs of the metabolic syndrome (hyperinsulinaemia and hypertriglyceridaemia combined), were found in nine (39%) of the bone-marrow transplantation patients compared with one (8%) of the 13 leukaemia patients and none of the healthy controls (p=0.0015). The frequency of insulin resistance increased with the time since bone-marrow transplantation. Abdominal obesity, but not overweight, was common among the patients with insulin resistance. INTERPRETATION: Long-term survivors of bone-marrow transplantation are at substantial risk of insulin resistance, impaired glucose tolerance, and type 2 diabetes even at normal weight and young age. They also develop typical signs of the metabolic syndrome. We advocate measurement of serum lipids, fasting blood glucose, and serum insulin for the follow-up of all patients who undergo transplants in childhood, to be continued regularly and possibly life-long.

Gene encoding a new RING-B-box-Coiled-coil protein is mutated in mulibrey nanism.

Mulibrey nanism (for muscle-liver-brain-eye nanism, MUL; MIM 253250) is an autosomal recessive disorder that involves several tissues of mesodermal origin, implying a defect in a highly pleiotropic gene. Characteristic features include severe growth failure of prenatal onset and constrictive pericardium with consequent hepatomegaly. In addition, muscle hypotonia, J-shaped sella turcica, yellowish dots in the ocular fundi, typical dysmorphic features and hypoplasia of various endocrine glands causing hormonal deficiency are common. About 4% of MUL patients develop Wilms' tumour. MUL is enriched in the Finnish population, but is rare elsewhere. We previously assigned MUL to chromosome 17q22-q23 and constructed a physical contig over the critical MUL region. The region has now been further refined by haplotype analysis and new positional candidate genes have been localized. We identified a gene with four independent MUL-associated mutations that all cause a frameshift and predict a truncated protein. MUL is ubiquitously expressed and encodes a new member of the RING-B-box-Coiled-coil (RBCC) family of zinc-finger proteins, whose members are involved in diverse cellular functions such as developmental patterning and oncogenesis.

Cohen syndrome: evaluation of its cardiac, endocrine and radiological features.

Cohen syndrome (MIM no. 216550) is an autosomal recessive disorder with a typical clinical picture. Since the first report, most publications have represented single case reports. In this study, our aim was to describe cardiac, endocrine and radiological abnormalities in 22 Cohen patients of Finnish descent. Detailed investigations of the heart revealed the anatomy of the heart to be normal with no evidence for clinically significant mitral prolapse. However, a decreased left ventricular function with advancing age was identified. No significant endocrine abnormalities were found at the examination of pituitary, adrenal and thyroid function. The height was either normal or patients were moderately short (mean height standard deviation score (SDS) - 2) at all ages, associated, however, often with the marked kyphosis. Truncal obesity was seen in 4/22 patients. X-rays of the chest, lumbar and thoracic spine, long bones, ankles and metacarpophalangeal pattern profiles revealed kyphosis, scoliosis and calcaneo planovalgus as common features. Fingers of these patients were slender but short with a characteristic metacarpophalangeal pattern profile.

High frequency of mutations in MODY and mitochondrial genes in Scandinavian patients with familial early-onset diabetes.

AIMS/HYPOTHESIS: To investigate the contribution of mutations in maturity-onset diabetes of the young (MODY) and mitochondrial genes to early-onset diabetes with a strong family history of diabetes in a cohort with a high prevalence of Type I (insulin-dependent) diabetes mellitus. METHODS: Screening for sequence variants in the hepatocyte nuclear factor (HNF)-4alpha (MODY1), glucokinase (MODY2), HNF-1alpha (MODY3) genes and mitochondrial DNA was carried out in 115 Finnish and Swedish patients with early-onset (

Growth hormone treatment of short children born small-for-gestational-age: the Nordic Multicentre Trial.

The aims of this study were to evaluate the efficacy and safety of different doses of growth hormone (GH) treatment in prepubertal short children born small-for-gestational-age (SGA). Forty-eight children born SGA from Sweden, Finland, Denmark and Norway were randomly allocated to three groups: a control group of 12 children received no treatment for 2 y, one group was treated with GH at 0.1 IU/kg/d (n=16), and one group was treated with GH at 0.2 IU/kg/d (n=20). In total 42 children completed 2 y of follow-up, and 24 children from the treated groups completed 3 y of treatment. Their mean (SD) age at the start of the study was 4.69 (1.61) y and their mean (SD) height was -3.16 (0.70) standard deviation scores (SDS). The children remained prepubertal during the course of the study. No catch-up growth was observed in the untreated group, but a clear dose-dependent growth response was found in the treated children. After the third year of treatment, the group receiving the higher dose of GH, achieved their target height. The major determinants of the growth response were the dose of GH used, the age at the start of treatment (the younger the child, the better the growth response) and the family-corrected individual height deficit (the higher the deficit, the better the growth response). Concentration of insulin-like growth factor-I (IGF-I) and IGF-binding protein-3 increased during treatment. An increase in insulin levels was found without negative effects on fasting glucose levels or glycosylated haemoglobin levels. GH treatment was well tolerated. In conclusion, short prepubertal children born SGA show a dose-dependent growth response to GH therapy, and their target height SDS can be achieved within 3 y of treatment given GH at 0.2 IU/kg/d. However, the long-term benefit of different regimens of GH treatment in children born SGA remains to be established.

Assignment of the mulibrey nanism gene to 17q by linkage and linkage-disequilibrium analysis.

Mulibrey nanism (MUL) is an autosomal recessive disorder with unknown basic metabolic defect. It is characterized by growth failure of prenatal onset, characteristic dysmorphic features, constrictive pericardium, hepatomegaly as a consequence of constrictive pericardium, yellowish dots in the ocular fundi, and J-shaped sella turcica. Hypoplasia of various endocrine glands, causing hormone deficiencies, is common. Here we report the assignment of the MUL gene, by linkage analysis in Finnish families, to a 7-cM region flanked by D17S1799 and D17S948 on chromosome 17q. Multipoint linkage analysis gave a maximum LOD score of 5.01 at loci D17S1606-D17S1853 and at D17S1604. The estimate of the critical MUL region was further narrowed to within approximately 250 kb of marker D17S1853 by linkage disequilibrium analysis. Positional candidate genes that belong to the growth hormone and homeobox B gene clusters were excluded. These data confirm the autosomal recessive inheritance of MUL and allow highly focused attempts to clone the gene.