Anastasios Papadimitriou

Screening for Type 1 Diabetes (T1D, incidence 1:300) with T1D autoantibodies (T1Ab) at ages 2 and 6, while sensitive, lacks a preventive strategy. Cholecalciferol 2000 IU daily since birth reduced T1D by 80% at 1 year. T1D-associated T1Ab negativized within 0.6 years with oral calcitriol in 12 children. To further investigate secondary prevention of T1D with calcitriol and its less calcemic analog, paricalcitol, we initiated a prospective interventional non-randomized clinical trial, the PRECAL study (ISRCTN17354692). In total, 50 high-risk children were included: 44 were positive for T1Ab, and 6 had predisposing for T1D HLA genotypes. Nine T1Ab+ patients had variable impaired glucose tolerance (IGT), four had pre-T1D (3 T1Ab+, 1 HLA+), nine had T1Ab+ new-onset T1D not requiring insulin at diagnosis. T1Ab, thyroid/anti-transglutaminase Abs, glucose/calcium metabolism were determined prior and q3–6 months on calcitriol, 0.05 mcg/Kg/day, or paricalcitol 1–4 mcg × 1–3 times/day p.o. while on cholecalciferol repletion. Available data on 42 (7 dropouts, 1 follow-up < 3 months) patients included: all 26 without pre-T1D/T1D followed for 3.06 (0.5–10) years negativized T1Ab (15 +IAA, 3 IA2, 4 ICA, 2 +GAD, 1 +IAA/+GAD, 1 +ICA/+GAD) within 0.57 (0.32–1.3) years or did not develop to T1D (5 +HLA, follow-up 3 (1–4) years). From four pre-T1D cases, one negativized T1Ab (follow-up 1 year), one +HLA did not progress to T1D (follow-up 3.3 years) and two +T1Ab patients developed T1D in 6 months/3 years. Three out of nine T1D cases progressed immediately to overt disease, six underwent complete remission for 1 year (1 month–2 years). Five +T1Ab patients relapsed and negativized again after resuming therapy. Four (aged <3 years) negativized anti-TPO/TG, and two anti-transglutaminase-IgA. Eight presented mild hypercalciuria/hypercalcemia, resolving with dose titration/discontinuation. Secondary prevention of T1D with calcitriol and paricalcitol seems possible and reasonably safe, if started soon enough after seroconversion.

Noonan syndrome (NS) is an autosomal dominant disorder characterized by clinical and genetic heterogeneity. It belongs to a wider group of pathologies, known as Rasopathies, due to the implication of genes encoding components of the Ras/MAPK signalling pathway. Recording the genetic alterations across populations helps assessing specific features to specific genes which is essential for better disease’s recognition, prognosis and monitoring. Herein, we report the clinical and molecular data of a Greek cohort comprising of 86 NS or NS-like patients admitted at a single tertiary Centre in Athens, Greece. The analysis was performed using Sanger and next-generation sequencing, comprising 14 different genes. The mutational rates of the confirmed NS-associated genes in the Greek NS population are as follows: PTPN11 32.5%; RIT1 5.8%; SOS1 4.7%; BRAF 1.2%; CBL 1.2%; KRAS 1.2%; MAP2K1 1.2%; RAF1 1.2%; SHOC2 1.2%, corresponding to 50% of positivity in total NS population. The genotype–phenotype analysis showed statistically significant differences in craniofacial dysmorphisms (p = 0.005) and pulmonary valve stenosis (PS) (p < 0.001) frequencies between patients harbouring a pathogenic variant and patients without pathogenic variant in any of the tested genes. Patients with at least a pathogenic variant had 6.71 times greater odds to develop PS compared to pathogenic variant-negative patients (OR = 6.71, 95%; CI = (2.61, 17.27)). PTPN11 positive patients showed higher frequency of epicanthal folds (p = 0.004), ptosis (p = 0.001) and coarseness (p = 0.001) and lower frequency of neurological findings (p = 0.006), compared to patients carrying pathogenic variants in other genes. Conclusion: Craniofacial dysmorphism and PS prevail among pathogenic variant positive compared to pathogenic variant negative NS and NS-like patients while neurological defects are less common in PTPN11-affected NS patients compared to patients harbouring pathogenic variants in other genes. The significant prevalence of the Ras/MAPK pathogenic variants (17.4%), other than PTPN11, in Greek NS patients, highlights the necessity of a wider spectrum of molecular diagnosis. What is Known: • Noonan syndrome (NS) has been associated with pathogenic variants in molecules-components of the Ras/MAPK pathway. • Clinical and genetic description of NS patients worldwide helps establishing personalized monitoring. What is New: • NS and NS-like mutational rate in Greece reaches 50% with pathogenic variants identified mostly in PTPN11 (32.5%), RIT1 (6%) and SOS1 (4.7%) genes. • The risk for pulmonary stenosis increases 6.71-fold in NS patients with a pathogenic variant compared to patients without genetic alterations.

Height velocity (HV) growth charts constructed from longitudinal studies are scarce as they have inherent difficulties, e.g., time, and costs. These difficulties can be partly overcome by a mixed-longitudinal study that covers the entire age range within 3–6 years. To construct HV charts of Greek children and to estimate the milestones of the adolescent growth spurt (AGS), i.e., the onset of AGS (take-off), peak HV, and total pubertal growth (TPG), we performed a mixed longitudinal study in 1514 Greek schoolchildren (6–18 years) with height measurements every 6 months during three schoolyears. We constructed HV charts for boys and girls. Take-off occurs earlier in girls, and, in both sexes, it precedes by 1–1.5 years the appearance of physical signs of puberty. PHV in boys occurs at 12.61 years and in girls at 10.93 years. At take-off, boys are 5 cm taller than girls and TPG for boys is 35.8 cm and for girls 27.3 cm. We constructed HV charts plotted by age, irrespective of pubertal status, and presented data on the milestones of AGS. Furthermore, we suggest that the gradual increase in IGF-1 and E2 that occurs after 5 to 6 years of age triggers the onset of AGS, which precedes physical signs of puberty.

In recent decades, pubertal onset in girls has been considered to occur at an earlier age than previously. Exposure to endocrine-disrupting chemicals (EDCs) has been associated with alterations in pubertal timing, with several reports suggesting that EDCs may have a role in the secular trend in pubertal maturation, at least in girls. However, relevant studies give inconsistent results. On the other hand, the majority of girls with idiopathic precocious or early puberty present the growth pattern of constitutional advancement of growth (CAG), i.e., growth acceleration soon after birth. Herein, we show that the growth pattern of CAG is unrelated to exposure to endocrine-disrupting chemicals and is the major determinant of precocious or early puberty. Presented data suggest that EDCs, at most, have a minor effect on the timing of pubertal onset in girls.

Purpose Studies examining association of estrogen receptor alpha (ERα) polymorphisms with early puberty are scarce and results are controversial; data in Caucasian girls are lacking. Main objective was to determine association of Xbal and Pvull polymorphisms of ERα gene in Greek girls with precocious/early puberty Methods We studied 107 girls with idiopathic precocious/early puberty and 81 young women with pubertal maturation within normal age (controls). Pubertal stage, height SDS (HSDS), and BMI z-score were determined in patients. In controls, height was measured and menarcheal age was self-reported. All participants in the study were genotyped for XbaI and PvuII polymorphisms of the ERα gene. Results There was no significant difference in XbaI and PvuII polymorphisms between patients and controls. Homozygous, xx and pp, girls had an earlier onset of puberty, although non-significant, than heterozygous or with no polymorphisms p = 0.9; in girls with pubertal onset p = 0.09. Girls with xxpp genotype were significantly taller, HSDS 1.63, p = 0.014. In controls, homozygosity for Xbal (xx) and PvuII (pp) was associated with significantly earlier menarche than in women with no polymorphism, p = 0.013 and p = 0.026, respectively, and xxpp genotype was associated with taller adult height, p = 0.017. Conclusion XbaI and PvuII polymorphisms are not related to idiopathic precocious/early puberty. Early pubertal girls homozygous for both polymorphisms presented earlier onset of puberty, although statistically non-significant, and taller height than girls heterozygous or without these polymorphisms. Homozygosity for both polymorphisms is associated with earlier menarche and taller adult height.

Loss-of-function mutations of IGSF1 are an X-linked cause of central hypothyroidism (CeH) and hypoprolactinemia. A boy who is now 15.2 years old presented at the age of 7.69 years for evaluation of obesity. Previous thyroid function evaluation suggested CeH (FT4 0.6 ng/mL, thyroid-stimulating hormone (TSH) 2.2 mIU/L] but his physician took no action. At presentation he was clinically and biochemically euthyroid, prepubertal and obese. Serum prolactin (PRL) was undetectable. Biochemistry was normal except for mild hypercholesterolemia, total cholesterol 198 mg/dL. Subsequently FT4 and TSH levels fluctuated between 0.72-0.95 ng/dL (normal 0.82.0) and 1.94-5.77 mIU/L (normal 0.3-5.0), respectively. Sequencing of IGSF1 gene revealed a novel genetic change c.3805C > T in exon 19; substitution of amino acid Arginine at position 1269 with a premature "stop" codon resulting in an altered protein product. The patient additionally presented delayed adrenarche, low height velocity that resolved spontaneously and normal pubertal onset associated with increased FSH levels. At 14 years-of-age, while the patient was at Tanner stage 4, PRL levels became detectable, rising gradually to 2.3 ng/mL at last examination. Thyroxine replacement therapy resulted in decrease in total cholesterol 103 mg/dL. A high index of suspicion for the disorder is needed since several measurements of thyroid function may be required for CeH to be disclosed. The patient's normal FT4 levels and normal intelligence would have resulted in a missed diagnosis if the serum PRI levels had not been measured. This case highlights the importance of measuring PRI in a boy with low normal FT4 and normal TSH levels.

Concerns over anxiety and depressive symptoms in children with premature adrenarche (PA) have been recently raised. However, to date, most relevant studies are on a small number of girls. In this cross-sectional study, 82 pre-pubertal children (66 girls and 16 boys) diagnosed with PA, were compared to 63 control children regarding their psychological characteristics and hypothalamic–pituitary–adrenal (HPA) axis function, as assessed by salivary cortisol measurement. Symptoms of anxiety and depression were assessed by child self-report (Spence Children’s Anxiety Scale (SCAS) and Depression self-rating scale for Children (DSRS)) and parent-report (Child Behaviour Checklist (CBCL)) tests validated for the Greek population. Salivary cortisol levels were determined directly after awakening (approximately 7am) and evening (8pm) of the same day. Morning serum DHEAS levels were assessed in PA children. Girls with PA scored significantly higher on anxiety (p = .016) and depression (p =.039) scales than controls. No group differences were noted for parent reports and children’s salivary cortisol concentrations. Boys with PA did not demonstrate significant differences in any of the aforementioned parameters. Our findings suggest that girls with PA may be at higher risk for reporting symptoms of anxiety and depression than their non-PA peers. HPA axis dysregulation in this population was not documented.