Silvana Salardi

Seven mutations in the human insulin gene linked to permanent neonatal/infancy-onset diabetes mellitus

Permanent neonatal diabetes mellitus (PNDM) is a rare disorder usually presenting within 6 months of birth. Although several genes have been linked to this disorder, in almost half the cases documented in Italy, the genetic cause remains unknown. Because the Akita mouse bearing a mutation in the Ins2 gene exhibits PNDM associated with pancreatic beta cell apoptosis, we sequenced the human insulin gene in PNDM subjects with unidentified mutations. We discovered 7 heterozygous mutations in 10 unrelated probands. In 8 of these patients, insulin secretion was detectable at diabetes onset, but rapidly declined over time. When these mutant proinsulins were expressed in HEK293 cells, we observed defects in insulin protein folding and secretion. In these experiments, expression of the mutant proinsulins was also associated with increased Grp78 protein expression and XBP1 mRNA splicing, 2 markers of endoplasmic reticulum stress, and with increased apoptosis. Similarly transfected INS-1E insulinoma cells had diminished viability compared with those expressing WT proinsulin. In conclusion, we find that mutations in the insulin gene that promote proinsulin misfolding may cause PNDM.

Short stature and celiac disease: A relationship to consider even in patients with no gastrointestinal tract symptoms

To determine the incidence of celiac disease in a group of nonselected children with short stature, duodenal biopsy was performed in 60 unselected children with short stature (below third centile) and absence of gastrointestinal tract symptoms. Examination revealed probable celiac disease in five children (8.3%). Analysis of the results of other tests that might possibly be considered as alternatives to biopsy (e.g., xylose test, antireticulin antibodies, gastrointestinal tract symptoms in the first two years of life, bone age, serum iron, iron load, triglyceride load) led us to conclude that no test or clinical measurement could have allowed us 100% certainty in making the correct diagnosis. None of the children with celiac disease had growth hormone deficiency. We conclude that asymptomatic celiac disease represents a cause of short stature that cannot be ignored, and that only by intestinal biopsy can all such patients be identified.

Prevalence of Celiac Disease in Children With Type 1 Diabetes Mellitus Increased in the Mid-1990s: An 18-year Longitudinal Study Based on Anti-endomysial Antibodies

Between 1987 and 2004, 331 consecutive children, all newly diagnosed with type 1 diabetes mellitus in our pediatric clinic, underwent repeated serological screening for celiac disease (CD) by means of anti-endomysial antibodies, measured prospectively between 1994 and 2004, and retrospectively, using frozen banked serum, between 1987 and 1993. There were 22 cases (6.6%) of biopsy-proven CD among the 331 diabetic children. The prevalence of CD was significantly (P = 0.015) higher after 1994 (10.6%) than before 1994 (3.3%). The rapid change in the risk of CD among Italian diabetic children that occurred in the mid-1990s could be related to changes in environmental factors, namely, eating habits and viral infections.

Quality of life, psychological adjustment and metabolic control in youths with type 1 diabetes: a study with self- and parent-report questionnaires.

Objective:  To evaluate self and parent reports on quality of life (QoL) and psychological adjustment of youths with type 1 diabetes, in comparison to a general paediatric population, and identify relationships between disease duration, metabolic control and psychological parameters.

Pelvic ultrasonography in girls with precocious puberty, congenital adrenal hyperplasia, obsesity, or hirsutism

Real-time ultrasonography of the pelvic organs was performed on 151 girls with various complete and incomplete forms of precocious puberty, 20 girls with congenital adrenal hyperplasia, 20 with hirsutism, 18 with obesity, and 133 age-matched normal girls. Uterine and ovarian volumes were calculated and the ovarian morphologic picture was classified as homogeneous, nonhomogeneous (less than three small cystic areas), microcystic (four or more small cystic areas less than 9 mm in diameter), follicular (at least one cystic area greater than 9 mm), and macrocystic (large cystic area greater than 20 mm). Ultrasound imaging allowed an easy distinction between true precocious puberty and premature thelarche or idiopathic premature adrenarche. It was also helpful in the diagnosis of transient sexual precocity, although in these cases the differential diagnosis of precocious puberty can be difficult. In postmenarcheal patients with congenital adrenal hyperplasia, ultrasound study showed a low uterine volume and, frequently, a macrocyst in the ovary. In hirsute girls and in a few obese patients, ovaries had an increased volume and a microcystic structure, similar to those in polycystic ovary syndrome. Pelvic ultrasonography can be useful not only in diagnosing disorders in sexual development but also for greater understanding of the pathogenesis of these and other disorders.

CAN ANTIGLIADIN ANTIBODY DETECT SYMPTOMLESS COELIAC DISEASE IN CHILDREN WITH SHORT STATURE

Duodenal biopsy and tests for antigliadin antibodies were done in 108 children with short stature unassociated with gastrointestinal symptoms. Other investigations for causes of growth failure were also carried out. In 88 patients, the cause of short stature could not be determined (group I). In 9 patients (8.3%) biopsy showed total villous atrophy, indicating probable coeliac disease (group II), while 7 patients had mild partial villous atrophy (group III). 4 patients (3.7%) had complete growth hormone deficiency. Antigliadin antibodies detected by immunofluorescence (IFL-AGA) were positive in 8 of the 9 group II patients. Symptomless coeliac disease is therefore a commoner cause of short stature than is hypopituitarism; by use of the IFL-AGA test it is possible to select patients for biopsy, thereby identifying most of the coeliac patients. If duodenal biopsies had been limited to IFL-AGA positive patients, 18 biopsies would have been carried out and coeliac disease would have been diagnosed in 8 of the 9 patients.

Relationships Between Growth Factors (Somatomedin-C and Growth Hormone) and Body Development, Metabolic Control, and Retinal Changes in Children and Adolescents With IDDM

We used the radioimmunoassay (RIA) method to determine somatomedin-C (SmC) basal values in 59 diabetic children and adolescents (20 prepubertal and 39 pubertal subjects; age range 2.75–20.16 yr; duration of diabetes 0.08–15.83 yr) and in 274 control subjects. In comparing diabetic subjects with controls, we considered only those 50 diabetic subjects who were age matched with the controls, i.e., those not over 16 yr chronological age. SmC basal levels in pubertal diabetic patients were no different from those of pubertal age-matched control children, whereas in prepubertal diabetic patients SmC was significantly lower than in the respective control children (P < .001). No correlation was found between the z score for SmC (i.e., the number of standard deviations each SmC level is from the age- and sex-normalized mean) and duration of disease, velocity standard deviation score, severity of fluoroangiographic retinal changes, basal C-peptide values and HbA, levels. No differences were encountered in mean SmC and SmC z-score values in the separate groups of poorly, fairly, and well-controlled diabetic children, in the groups with and without residual pancreatic activity, and in the group with and without retinal changes. In 16 of the pubertal diabetics and in 15 pubertal controls, serum glucose, growth hormone (GH), and SmC concentrations were determined during the night. The integrated nocturnal secretion of SmC was no different in diabetics than in controls, whereas the integrated nocturnal secretion of GH was significantly (P < .025) higher in diabetics than in controls. These data suggest a partial block in somatomedin production, which would be compensated by a hypersecretion of GH through a negative-feedback relationship. On the other hand, it may be that GH hypersecretion is primary and that the normal or low SmC secretion is a response to low-efficiency GH.

Microalbuminuria in diabetic children and adolescents : relationship with puberty and growth hormone

ABSTRACT. Urinary albumin excretion (UAE) was determined by radioimmunoassay in two 24 h urine collections from 125 diabetic children and adolescents and from 71 normal children matched for age and sex. Thirteen patients (10.4%) aged > 12 years had microalbuminuria, i. e. log transformed UAE levels above the upper normal range (24.5 mg/24 h). UAE values were positively correlated with age, GH secretion, but not with duration of disease, glycosylated hemoglobin, renal size or N‐acetyl‐beta‐glucosaminidase excretion. Diabetic normoalbuminuric children aged 10 years and older had significantly higher UAE than controls and than younger diabetic patients matched for duration of disease. HLA DR3/DR4 heterozygosity frequency was significantly higher (p<0.01) in the microalbuminurine group than in the normoalbuminuric. All microalbuminuric subjects (n=8) with short duration of disease (3.92 ± 3.43 yr) developed diabetes at puberty. In conclusion, our cross‐sectional study suggests: if a number of factors are combined, i. e. HLA DR3/DR4 heterozygosity, onset of disease at puberty and higher GH values, the probability of developing abnormal levels of UAE will increase.

Blood coagulation changes in homocystinuria: Effects of pyridoxine and other specific therapy

The aim of this study was to investigate the blood coagulation changes in three patients with homocystinuria, in baseline condition and during therapy. At baseline, antithrombin III activity and factor VII levels were reduced in all three patients; antithrombin III protein and protein C antigen were also slightly lowered in one patient, and factor X in another. beta-Thromboglobulin, a measure of platelet activation, was increased in one case. During pyridoxine treatment, antithrombin III activity was rapidly restored to normal; factor VII increased and beta-thromboglobulin decreased. These data suggest that, in addition to platelet activation, abnormalities of blood clotting, and particularly reduction of antithrombin III, may play a role in the thrombotic tendency associated with homocystinuria. The nature of these clotting alterations is still uncertain, but their improvement during active metabolic treatment suggests that the defect in amino acid transsulfuration of homocystinuria may directly affect synthesis or activity of some liver-dependent clotting factors.

Prevalence and Characteristics of Coeliac Disease in Type 1 Diabetes Mellitus

Coeliac disease in patients with insulin-dependent diabetes mellitus has been reported (1-3) and the appearance of diabetes mellitus in subjects with coeliac disease in also well-known. In our recent study regarding a group of children with short stature (7), we reported that antigliadin antibody evaluation is the test most suited for this purpose. Thus, we used this method to study the exact prevalence of coeliac disease in a group of children and adolescents with type 1 diabetes mellitus. We examined 146 children and adolescents with insulin-dependent diabetes mellitus (IDDM) (76 males and 70 females) aged 2 3/12-22 7/12 years (mean k SD = 11.42?5.16), in whom duration of the disease varied from 0 to 17 2/12 years (mean f SD = 4.25k4.25). None of the children had gastrointestinal symptoms suggesting coeliac disease. A serum sample for antigliadin antibodies (AGA) as determined by immunofluorescence (IFL-AGA) (8) or by ELISA (ELISA-AGA) (6), islet cell antibodies (ICA), complement fixing islet cell antibodies (CfICA), thyorid microsomal (TMA), gastric parietal autoantibodies (PCA), liver-kidney microsome antibodies (LKM), non organ specific autoantibodies was obtained from each patient. Sixtynine patients were typed for HLA A, B, C and DR antigens. All patients who had antigliadin antibodies underwent jejunal biopsy. Informed consent was obtained from the parents and the children. Students t-test and 2 was used to analyze the results.