Daniela Larizza

Prevalence of metabolic syndrome (MS) in children and adolescents with varying degrees of obesity

Objective  Childhood obesity is increasingly common and is associated with health problems; in particular, obesity plays a central role in the metabolic syndrome (MS). We estimated the prevalence of MS in Caucasian children and adolescents with varying degrees of obesity.

Autoimmune stigmata in Turner syndrome: when lacks an X chromosome.

An increased frequency of autoimmune diseases as well as an elevated incidence of autoantibodies has been observed in patients with Turner syndrome; the most common autoimmune diseases appear to be thyroid autoimmune disease and inflammatory bowel diseases. Turner patients evolve towards autoimmunity much more frequently than people with normal karyotype without any relevant excess of the putative immunogenetic risk markers. That underscores the great influence of X-chromosome abnormalities in the development of autoimmune disorders and suggests an epistatic interaction of X genes with immune response genes. Interestingly, one of the human MHC-paralogues is located in the long arm of the X chromosome, so that who is defective in this region might be less efficient to control the pathogenic repertoire during the lifespan. Medical care for patients with TS should routinely include screening for the autoimmune disorders in order to assure early detection and appropriate treatment.

Final height in Turner syndrome patients treated with growth hormone.

Growth hormone (GH), alone or in combination with anabolic steroids, seems to improve the growth rate in Turner syndrome, but to exert a less striking effect on the final height (FH). Reports on the FH usually lack a control group, and the GH effect is determined using the gain in centimeters over projected height. Out of a cohort of 32 Turner syndrome girls under recombinant human GH (rhGH) therapy (0.5 IU/kg/week during the 1st year and 1 IU/kg/week subsequently), 18 (treated for 3-6 years) attained FH. The mean chronological age at the first examination was 9.6 +/- (SD) 2.1 years and at the start of GH therapy 13.0 +/- 2.0 (range 8.8-17.2) years. Eighteen untreated subjects matched for chronological age and karyotype served as control group. The FH as SDS according to Lyon and to unpublished Italian Turner syndrome girl standards was not significantly different as compared with pretreatment. In comparison with Italian cross-sectional Turner syndrome standards (FH 142.5 +/- 7.0 cm), the FH of the control group was quite similar (142.2 +/- 4.9 cm), whereas the rhGH-treated group showed a FH of 147.6 +/- 7.3 cm with a mean increment of about 5 cm. The height gain during therapy (as delta height in SDS either according to Lyon or to Italian SDS standards) was compared for each girl with that of a matched girl of the control group during a comparable observation period. A significantly different delta height was observed in the treated versus control groups: 0.3 +/- 1.1 vs. -1.0 +/- 0.8 according to Lyon (p < 0.001) and 0.8 +/- 0.7 vs -0.3 +/- 0.5 according to Italian standards (p < 0.001). If we compared the FH with the projected height according to Lyon standards, the height gain (as delta height in cm) was significantly higher than in the untreated subjects (-1.1 +/- 4.8 vs. -6.2 +/- 3.9 cm; p < 0.05). It seems worthwhile to undertake GH treatment in Turner syndrome girls who represent a very short stature population, even though the response is less significant than in classic GH deficiency and shows a striking variability, probably due to a sort of peripheral resistance.

Hypopituitarism and Stalk Agenesis: A Congenital Syndrome Worsened by Breech Delivery?

Thirty-seven patients with idiopathic hypopituitarism, of whom 12 had multiple pituitary hormone deficiencies (MPHD) and 25 isolated growth hormone deficiency (IGHD), were evaluated by magnetic resonance imaging (MRI). Twenty-two of the 37 showed congenital anterior pituitary hypoplasia, stalk agenesis and ectopic posterior pituitary gland at the infundibular recess (group A), while the remaining 15 presented isolated anterior pituitary hypoplasia (group B). Perinatal histories obtained from all patients demonstrated that 18/22 children of group A (81.81%) had histories of adverse perinatal events, with breech presentation in 15 (68.18%). Twelve of 12 children of group A born by breech delivery developed MPHD; 3 born by cesarean section for breech presentation had only IGHD. Patients of group B had also a high incidence of perinatal insults (12/15, 80%), but breech delivery was markedly less frequent (13.33 vs. 68.18% of group A) and responsible for only IGHD. Group B had also higher percentages of maternal spontaneous abortion and low birth weight. Our study suggests that several factors may play a role in the development of growth hormone deficiency. Some patients had severe perinatal insults apparently leading to hypopituitarism. We were able to define by MRI a group of patients with congenital abnormalities, such as anterior pituitary hypoplasia, stalk agenesis and posterior pituitary ectopia, among whom breech presentation was very common. In this group, breech delivery was always followed by MPHD while cesarean or normal delivery in such patients was followed by IGHD only.

Hypothalamic-pituitary dwarfism: Comparison between MR imaging and CT findings

Magnetic Resonance (MR) imaging was carried out on 33 patients with idiopathic growth hormone deficiency, in 22 of whom CT scan had been carried-out previously. Twenty-one patients presented some complications at birth. Both MR and CT were positive in the evaluation of the sella. MR imaging exhibited a higher degree of accuracy than CT in the evaluation of pituitary gland, pituitary stalk and brain anomalies.On the basis of pituitary morphology demonstrated by MR imaging, and perinatal histories, a classification is proposed which divides our patients into three group: A) a first group of 13 patients presenting severe hypoplasia of the anterior pituitary lobe, hypoplasia of the stalk and ectopia of posterior lobe. The underlying cause of these anatomic defects might be developmental in origin, and date from early intrauterine life, probably worsened at birth. B) a second group of 10 patients presenting severe hypoplasia of the anterior pituitary lobe. A perinatal event and birth trauma might be responsible for pituitary damage. C) a third group of 10 patients with no morphological abnormalities of the pituitary gland. A derangement of the neuroendocrine mechanism which control the growth hormone secretion might account for these patients.

An analysis of Xq deletions

We characterized by fluorescence in situ hybridization and Southern blotting 14 partial Xq monosomies, 11 due to terminal deletions and 3 secondary to X/autosome translocations. Three cases were mosaics with a XO cell line. In view of the possible role played by telomeres in chromosome segregation, we hypothesize a relationship between the loss of telomeric sequences in terminal deletions and the presence of 45,X cells. A correlation between phenotype and extent of deletion revealed that there is no correspondence between the size of the deletion and impairment of gonadal function. Turner stigmata are absent in patients without an XO cell line, when the breakpoint is distal to Xg24. A low birthweight is present whenever the breakpoint is at q22 or more proximal.

Turner's syndrome in Italy: familial characteristics, neonatal data, standards for birth weight and for height and weight from infancy to adulthood.

In 1990, the Italian Study Group for Turners Syndrome (ISGTS) undertook a nationwide survey, involving the retrospective collection of cross‐sectional data and longitudinal growth profiles of 772 girls with Turners syndrome born between 1950 and 1990. The study was carried out in 29 pediatric endocrinological centers. In this first report, the familial characteristics and neonatal data of Turner girls are described, compared to those of the general population, and related to postnatal somatic development. Furthermore, charts for birth weight and growth standards for height and weight from infancy to adulthood are presented (these are the first charts based on a large sample from the Mediterranean area). The main findings were: (1) incidence of Turner births increases with parental age or parity; (2) most of the neonates are small for dates; (3) girls with normal birth weight tend to be both taller and heavier than girls with low birth weight during the whole growth period; and (4) a 10‐cm difference in midparental height leads to a 6.5‐cm difference in adult stature.

Autoimmunity, HLA, Gm AND Km Polymorphisms in Turner's Syndrome

Considering the high frequency of autoimmune disorders in Turners syndrome and the close relationship between autoimmunity, HLA and immunoglobulin constant region gene polymorphisms, we studied 46 patients with Turners syndrome, by determination of autoantibodies, HLA histoglobulins and Gm and Km allotypes. OSA and in particular PCA resulted significantly more frequent in patients than in the controls. A higher frequency of HLA-A31, B38 antigens and of blanks at HLA-A locus was found in Turners subjects than in the controls. A31 was significantly more frequent in autoantibody positive patients while B38 was more frequent in autoantibody negative Turners subjects than in the controls. DR4 antigen was present only in autoantibody negative patients. Gm 3; 23; 5* phenotype was significantly less frequent, while Gm 3;..; 5* phenotype was more frequent in patients than in controls. Our data confirm the higher incidence of autoimmunity disorders in Turners syndrome than in normal subjects. Particular HLA and immunoglobulin types seem to mark this condition. The increase in the blank frequency at A locus could be explained by the presence of a rare antigen at HLA-A locus or a particularly elevated homozygous condition in these subjects.

Serum liver enzymes in Turner syndrome.

Abstract Increased serum concentrations of liver enzymes are sometimes observed, in the absence of clinical symptoms of liver disease, in patients with Turner syndrome. The purpose of this study was to evaluate, in our Turner patients, serum liver enzyme levels and to find a cause for their increase. In 70 Turner patients, serum AST, ALT, GGT levels were evaluated every 6 months during a period of 0.8–21.9 years. In patients in whom increased values of liver enzymes were found, serological markers for infectious hepatitis, serum hepatitis C virus RNA and virus genotype, IgG and IgA antibodies to gliadin and endomysium, coeruloplasmin, copper, α1-antitrypsin, total proteins and electrophoresis, IgG, IgA, IgM, fibrinogen, prothrombin, alkaline phosphatase, creatine kinase and total and direct bilirubin were also determined. Antinuclear, anti-smooth muscle and anti-liver-kidney microsome antibodies together with antithyroglobulin and anti-thyroid peroxidase antibodies were determined in all patients and in 166 age-matched female controls. In 22 patients, increased liver enzymes were observed, not related to karyotype. Follow-up showed that the hepatic disorder did not worsen with the time. Serological markers of hepatitis C virus were positive in three patients. When the serum liver enzyme increase was first observed in the other 19 patients with high enzyme levels (group A), 14 patients had never been submitted to hormonal treatment, 4 were on oestrogen/gestagen treatment and 1 was being treated with both growth hormone and oestrogen. Coeliac disease, α1-antitrypsin deficiency and Wilson disease were ruled out by appropriate investigations. In 8/19 group A patients, antinuclear and/or anti-smooth muscle antibodies were present versus 6/48 of patients with normal liver enzymes (group B). Thyroid antibodies were found in 8/19 patients in group A and in 13/48 in group B. Weight excess SDS was significantly higher in Turner girls with liver enzyme increase. Ultrasonography, performed in 17 patients of group A, showed mild hepatomegaly in 4 and increased echogenicity with fatty infiltration in 6. Conclusion Hepatic abnormalities in Turner syndrome are not progressive. Oestrogen should not be considered the main cause of increased liver enzymes in Turner syndrome since most of our patients with this finding had not been previously treated with oestrogens. An auto-immune pathogenesis might be considered in some cases, whereas the association with weight excess seems the most frequent cause of liver disorder in Turner syndrome.

Auto-immunity in children with diabetes mellitus and in their relatives.

Islet cell antibodies (ICA-IgG and complement-fixing-ICA), parietal cell antibodies (PCA), intestinal epithelial cell antibodies (IECA), thyroglobulin (TgA) and thyroid microsomal antibodies (MsA), antinuclear (ANA) and reticulin antibodics (RA), were studied in 55 insulin-dependent diabetic patients (30 males and 25 females), aged 2–19 years with diabetes from a few days up to 14 years. In 58% of the diabetics one or more autoantibodies were found: ICA-IgG (31%), CF-ICA (16%), PCA (34%), TgA (9%), MsA (9%), ANA (13%), RA (2%). Autoantibodies were significantly more frequent in females (76%) than in males (43%) (P<0.025). ICA-IgG, CF-ICA, PCA, ANA were significantly more frequent in patients than in controls. The frequency of ICA-IgG and CF-ICA was significantly higher during the first 3 years of disease than afterwards (P<0.001); a similar pattern was observed for PCA, TgA, MsA. Of the 87 parents and 30 siblings screened for ICA-IgG, CF-ICA, PCA, IECA, TgA, MsA, ANA and RA, 42 (44%) had one or more autoantibodies, which were more frequent in females than in males. Seven relatives (6%) were ICA-IgG positive (four mothers, two fathers and one brother), and only one mother, ICA-IgG negative, was CF-ICA positive. Other autoantibodies were also more frequent in parents than in controls. Autoantibody-positive relatives have been asymptomatic up to now.