Cristina Manoni

Bone density and metabolism in subjects with microdeletion of chromosome 22q11 (del22q11)

INTRODUCTION Although hypoparathyroidism with hypocalcaemia is one of the most frequent clinical features of monoallelic microdeletion of chromosome 22q11 (22q11DS), bone mass and metabolism have not yet been assessed in these patients. DESIGN This study aimed to evaluate bone mass and metabolism in a cohort of patients, both children and adults, with 22q11DS. METHODS In twenty-eight patients with 22q11DS (median age 12.5, range 6.1-42.8 years), serum levels of ionised and total calcium, phosphate, parathyroid hormone (PTH), 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, osteocalcin and bone-specific alkaline phosphatase (BSAP), and urinary deoxypyridinoline concentrations were evaluated. In these patients, bone mineral density (BMD) was evaluated by dual-energy X-ray absorptiometry (DXA) examination, and volumetric BMD (bone mineral apparent density (BMAD)) was calculated. The data obtained from paediatric and adult patients were compared with two age-, sex- and body size-matched healthy subject control groups. RESULTS Patients with 22q11DS showed a reduced BMAD Z-score compared with controls (P<0.001). These patients also had significantly lower ionised (P<0.001) and total calcium (P<0.05) levels as well as lower PTH levels (P<0.05), compared with the controls. In particular, children and young patients with 22q11DS had significantly lower serum osteocalcin levels (P<0.001), BSAP levels (P<0.001) and urinary deoxypyridinoline concentrations (P<0.001) than controls. These results were not confirmed in adults. Finally, patients with hypoparathyroidism and/or hypocalcaemia at the time of the study showed significantly lower ionised (P<0.001) and total calcium levels (P<0.001), PTH levels (P<0.05), BSAP levels (P<0.001), osteocalcin levels (P<0.001) and urinary deoxypyridinoline concentrations (P<0.001), compared with patients without hypoparathyroidism and/or hypocalcaemia. Nonetheless, the BMAD Z-score did not show substantial differences between these two groups. CONCLUSIONS Subjects with 22q11DS have a significant reduction in bone mass that appears to be more severe in adults who have already attained peak bone mass than in children who are still growing. Therefore, we suggest a close monitoring of bone mass and metabolism in 22q11DS patients.

Determinants of Vitamin D Levels in Italian Children and Adolescents: A Longitudinal Evaluation of Cholecalciferol Supplementation versus the Improvement of Factors Influencing 25(OH)D Status.

Objective. This paper aims to assess 25(OH)D levels in Italian children and adolescents identifying risk factors for 25(OH)D deficiency and to evaluate whether a normal 25(OH)D value can be restored in 25(OH)D-deficient patients. Methods. We evaluated 25(OH)D levels in 679 Italian children and adolescents (≤10, 11–20, 21–30, and >30 ng/mL were defined as severe deficiency, deficiency, insufficiency, and sufficiency, resp.). Of these, 365 25(OH)D-deficient were followed up for 1 year; 205 were treated with cholecalciferol (Arm A: 400 I.U.) and 160 by improving the environmental variables influencing 25(OH)D levels (Arm B). Results. At cross-sectional evaluation, 11.3% showed sufficiency, 30.0% insufficiency, and 58.7% 25(OH)D deficiency. Mean 25(OH)D was 19.08 ± 8.44 ng/mL. At the enrollment time (T 0), no difference was found between Arms A and B with respect to distribution and 25(OH)D levels. At end time (T 1) 26.0% (29.7% in Arm A versus 20.6% in Arm B) showed sufficiency, 38.4% (42.0% versus 34.4%) insufficiency, and 35.6% (28.3% versus 45.0%) 25(OH)D deficiency. Mean 25(OH)D level was 23.71 ± 6.83 ng/mL. Conclusions. Neither changes of lifestyle nor 400 I.U. cholecalciferol supplementation alone appears to be sufficient to restore adequate 25(OH)D levels.

Thyroid Hypoplasia as a Cause of Congenital Hypothyroidism in Williams Syndrome

In the Williams-Beuren syndrome (WBS), disorders of the thyroid function and morphology have been reported and programs of thyroid screening and surveillance are recommended. However, the frequency of biochemical thyroid assessment, particularly in the first year of life, is being debated. In this report we describe an infant with WBS and congenital hypothyroidism, due to an important thyroid hypoplasia. The patient, a 1-month-old female, negative at primary neonatal thyroid screening, was referred to our hospital for dyspnea. Thyroid function tests showed a raised TSH (42 mIU/l; normal range 0.5–4 mIU/l) with a low FT4 concentration (10.21 pmol/l; normal range: 10.29–24.45 pmol/l). Ultrasound examination of the neck showed a significant thyroid hypoplasia, whereas 99mTc-pertechnetate thyroid scintigraphy evidenced a thyroid gland in normal position, with reduced shape and overall weak fixation. Therefore, treatment with L-thyroxinewas started. Thyroid hypoplasia is a frequent characteristic of WBS and abnormalities of thyroid function are common in patients with this feature. Therefore, the possibility of congenital hypothyroidism should always be taken into consideration too and, even if congenital hypothyroidism neonatal screening is negative, thyroid (morphology and function) evaluation should be regularly assessed when the diagnosis is made and, thereafter, every year in the first years of life.

Diabetes mellitus in a girl with thyroid hormone resistance syndrome: a little recognized interaction between the two diseases

The syndrome of resistance to thyroid hormone (RTH) is characterized by elevated serum free thyroid hormones (FT4 and FT3) in the presence of unsuppressed TSH levels, reflecting resistance to the normal negative feedback mechanisms in the hypothalamus and pituitary. The degree of resistance within peripheral tissues determines whether thyrotoxic clinical features are associated with this condition. Classic features include attention deficit hyperactivity disorder, growth delay, tachycardia, and goiter. However, other features, such as frequent ear, nose and throat infections, hearing deficit, and decreased bone mass have recently been recognized. The phenotype of RTH is variable, with most patients presenting with mild to moderate symptoms. In this report we describe a girl with familiar RTH and diabetes mellitus. This is, to our knowledge, the first report regarding this association. Nearly one year after long-term triiodothyroacetic acid (Triac) therapy, we observed a reduction of thyroid hormone levels with an amelioration of insulin resistance. The possible interactions between these disorders are discussed.

Bone mineral status and metabolism in patients with Williams-Beuren syndrome.

OBJECTIVE: To evaluate bone mineral status and metabolism in a cohort of patients with Williams-Beuren syndrome (WBS). PATIENTS: Thirty-one children (15 females, 16 males; mean age 9.6±2.74 years) and 10 young adults (6 females, 4 males; mean age 21.4±5.11 years) with WBS were cross-sectionally evaluated and compared with two age-, sex-, and body-size-matched paediatric (155 subjects, 75 females and 80 males; mean age 9.7±2.93 years) and adult (50 subjects, 30 females and 20 males; mean age 22.3±5.42 years) healthy controls. MEASUREMENTS: We evaluated ionised and total calcium, phosphate, parathyroid hormone (PTH), 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, osteocalcin, bone alkaline phosphatase levels, and urinary deoxypyridinoline concentrations. We also calculated the phalangeal amplitude-dependent speed of sound (AD-SoS) and the bone transmission time (BTT) z-scores. RESULTS: WBS patients showed a significantly reduced AD-SoS z-score (p <0.001) and BTT z-score (p <0.001) compared with the controls. This finding persisted when we divided the sample into paediatric and adult patients. WBS patients also had significantly higher ionised (p <0.001) and total calcium (p <0.001) levels as well as higher PTH levels (p <0.001) compared with the controls. Furthermore, WBS children and adolescents had significantly lower serum osteocalcin levels (p <0.001) and urinary deoxypyridinoline concentrations (p <0.001) than controls. CONCLUSIONS: WBS subjects exhibit a significant reduction in bone mineral status and impaired bone metabolism. These findings point to the need for close monitoring of WBS patients.

Increased risk of coeliac disease in patients with congenital hypothyroidism.

Background: In patients with congenital hypothyroidism (CH), the presence of coeliac disease (CD) has been sporadically described. Methods: Seventy-nine consecutive children (58 females and 21 males; age range 3.1–12.1 years) with permanent CH were studied. For all patients, a family history of autoimmune diseases as far as second-degree relatives was collected, and total serum IgA, antigliadin, anti-endomysium and anti-transglutaminase antibodies were evaluated. In the subjects positive for CD antibodies, the CD diagnosis was confirmed by jejunal biopsy. One hundred and eighty-two Italian children from the same geographical area, matched for age and sex, acted as controls. Results: In CH patients, a statistically significant difference was found in the familial occurrence of autoimmune diseases compared to controls (22 vs. 7.9%; p < 0.001). A total of 6 patients (4 girls, 2 boys; 7.6 vs. 1%; p < 0.005) were positive for CD antibodies. In 5 of these patients (6.3%), the diagnosis of CD was confirmed histologically. Conclusion: Our data show a higher prevalence of CD in children with permanent CH and suggest that these patients should be monitored carefully for CD. Other studies are needed to confirm our results and to explain the causes of this possible relationship.

Bone Mineral Status in Children and Adolescents with Klinefelter Syndrome.

Objective. Klinefelter syndrome (KS) has long-term consequences on bone health. However, studies regarding bone status and metabolism during childhood and adolescence are very rare. Patients. This cross-sectional study involved 40 (mean age: 13.7 ± 3.8 years) KS children and adolescents and 80 age-matched healthy subjects. For both patient and control groups, we evaluated serum levels of ionised and total calcium, phosphate, total testosterone, luteinising hormone, follicle stimulating hormone, parathyroid hormone (PTH), 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D, osteocalcin, bone alkaline phosphatase, and urinary deoxypyridinoline concentrations. We also calculated the z-scores of the phalangeal amplitude-dependent speed of sound (AD-SoS) and the bone transmission time (BTT). Results. KS children and adolescents showed significantly reduced AD-SoS (p < 0.005) and BTT (p < 0.0005) z-scores compared to the controls. However, KS patients presented significantly higher PTH (p < 0.0001) and significantly lower 25(OH)D (p < 0.0001), osteocalcin (p < 0.05), and bone alkaline phosphatase levels (p < 0.005). Interestingly, these metabolic bone disorders were already present in the prepubertal subjects. Conclusions. KS children and adolescents exhibited impaired bone mineral status and metabolism with higher PTH levels and a significant reduction of 25-OH-D and bone formation markers. Interestingly, this impairment was already evident in prepubertal KS patients. Follow-ups should be scheduled with KS patients to investigate and ameliorate bone mineral status and metabolism until the prepubertal ages.

Autoimmune Thyroiditis, Pernicious Anaemia, Vitiligo and Scleroatrophic Lichen in a boy with short-chain acylCoA dehydrogenase deficiency.

Short-chain acylCoA dehydrogenase (SCAD) deficiency is a rare mitochondrial disorder involving the β-oxidation of fatty acylCoA compounds in chains of 4–6 carbons. Unlike other mitochondrial disorders, cases involving autoimmune diseases have not been described. We report a 15-year-old boy with SCAD deficiency who suffered from pernicious anaemia, vitiligo, scleroatrophic lichen and autoimmune thyroiditis. As has been reported in other mitochondrial disorders, we hypothesised that autoimmune diseases are also present in SCAD deficiency. Furthermore, we discuss the possible pathogenetic relationship between these diseases.

Diabetes mellitus in a girl with thyroid hormone resistance syndrome: a unlooked feature for this condition?

The syndrome of resistance to thyroid hormone(RTH) is characterized by elevated serum free thyroid hormones (FT4and FT3) in the presence of unsuppressed TSH levels, reflecting resistanceto the normal negative feedback mechanisms within the hypothalamus andpituitary. The degree of resistance within peripheral tissues determineswhether thyrotoxic clinical features are associated with this condition.Classic features include attention deficithyperactivity disorder, growth delay, tachycardia, and goiter. However, otherfeatures, such as frequent ear nose and throat infections, hearing deficit, anddecreased bone mass have recently been recognized. The phenotype of RTH isvariable, with most patients presenting with mild to moderate symptoms.In this report we describe a girlwith familiar RTH and diabetes mellitus. This is, to our acknowledge, the firstreport regarding this association. Near 1 year after long-term triiodothyroaceticacid (Triac) therapy, we evidence a reduction of thyroid hormone levels, with anamelioration of insulin resistance. The possible interactions between these disordersare discussed.