Seroprevalence of Protective Antibodies Against Influenza and the Reduction of the Influenza Incidence Rate: An Annual Repeated Cross-Sectional Study From 2014 to 2019.

BACKGROUND: Seroepidemiological studies provide estimates of population-level immunity, prevalence/incidence of infections, and evaluation of vaccination programs. We assessed the seroprevalence of protective antibodies against influenza and evaluated the correlation of seroprevalence with the cumulative annual influenza incidence rate. METHODS: We conducted an annual repeated cross-sectional seroepidemiological survey, during June-August, from 2014 to 2019, in Portugal. A total of 4326 sera from all age groups, sex, and regions was tested by hemagglutination inhibition assay. Seroprevalence and geometric mean titers (GMT) of protective antibodies against influenza were assessed by age group, sex, and vaccine status (65+ years old). The association between summer annual seroprevalence and the difference of influenza incidence rates between one season and the previous one was measured by Pearson correlation coefficient (r). RESULTS: Significant differences in seroprevalence of protective antibodies against influenza were observed in the population. Higher seroprevalence and GMT for A(H1N1)pdm09 and A(H3N2) were observed in children (5-14); influenza B seroprevalence in adults 65+ was 1.6-4.4 times than in children (0-4). Vaccinated participants (65+) showed significant higher seroprevalence/GMT for influenza. A strong negative and significant correlation was found between seroprevalence and ILI incidence rate for A(H1N1)pdm09 in children between 5 and 14 (r = -0.84; 95% CI, -0.98 to -0.07); a weak negative correlation was observed for A(H3N2) and B/Yamagata (r ≤ -0.1). CONCLUSIONS: The study provides new insight into the anti-influenza antibodies seroprevalence measured in summer on the ILI incidence rate in the next season and the need for adjusted preventive health care measures to prevent influenza infection and transmission.

Pilot Study on Newborn Screening for Spinal Muscular Atrophy.

INTRODUCTION: Newborn screening (NBS) in Portugal is a significant public health measure to provide early detection for specific disorders so that early treatment is possible. Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder that causes degeneration of anterior horn cells in the human spinal cord and subsequent loss of motor neurons. Its incidence is estimated in 1.6000-11.800 live births. A pilot study on 100.000 newborns is being carried out at the neonatal screening laboratory with the aim of determining the specificity, sensitivity, and feasibility of the SMA screening at the NBS laboratory in Portugal. METHODS: The study presented here was based on data obtained from neonatal screening, involving the analysis of 25.000 newborns. SMA screening is performed by a qualitative detection of exon 7 of the SMN1 gene. The assay was performed using a commercially available real-time PCR, the Eonis SMN1, TREC, and KREC kit. RESULTS/CASE REPORT: The dried blood spots of a total of 25.000 newborns were tested; among these newborns, two were diagnosed as having SMA with survival motor neuron 1 (SMN1) deletion. These two SMA-positive samples were sent to a specialized clinical centre and a peripheral blood sample was sent to the reference laboratory for confirmation of the exon 7 deletion and determination of the SMN2 copy number. CONCLUSION: Early diagnosis and intervention are important for SMA treatment to be effective; the treatment should be started at the pre-symptomatic stage of SMA. Thus, newborn screening for SMA is strongly recommended. Currently, targeted therapies for SMA are available, and attempts are being made worldwide to include SMA screening in newborns.

Congenital adrenal hyperplasia with a CYP21A2 deletion overlapping the tenascin-X gene: an atypical presentation.

OBJECTIVES: Congenital Adrenal Hyperplasia (CAH) is a group of genetic diseases characterized by impaired cortisol biosynthesis. 95% of CAH cases result from mutation in the CYP21A2 gene encoding 21-hydroxilase. TNX-B gene partially overlaps CYP21A2 and encodes a matrix protein called Tenascin-X (TNX). Complete tenascin deficiency causes Enlers-Danlos syndrome (EDS). A mono allelic variant called CAH-X CH-1 was recently described, resulting from a CYP21A2 complete deletion that extends into the TNXB. This haploinsufficiency of TNX may be associated with a mild hypermobility form of EDS, as well as other connective tissue comorbidities such as hernia, cardiac defects and chronic arthralgia. CASE PRESENTATION: We report four patients heterozygous for a CAH-X CH-1 allele that do not present clinical manifestations of the EDS. CONCLUSIONS: All CAH patients, carriers of these TNXA/TNXB chimeras, should be evaluated for clinical manifestations related to connective tissue hypermobility, cardiac abnormalities and other EDS features, allowing for better clinical surveillance management.

[Portuguese Newborn Screening Program.] / Programa portugués de cribado neonatal.

The Portuguese Newborn Screening Program is a public health program that started in 1979, screening for PKU, being totally supported by public funds. It's a non-mandatory well implemented program that testes about 99.9% of Portuguese newborns. In the actual screening panel encompasses 26 disorders, including inborn errors of metabolism, congenital hypothyroidism and cystic fibrosis. Sample collection is advised to be made at 3rd day of life and treatment begins in average by the 10th day. Every testes are performed in one single national laboratory, that processes about 88,000 samples/year. In the 41 years of program existence, more than 3,800,000 newborns were screened and 2,130 affected newborns detected, reflecting the positive impact of the Program in the population. Future perspectives include the increase of program value in terms of public health by optimizing the screening of the disorders already screened and evaluation the possibility of adding others.

El Programa Portugués de Cribado Neonatal es un programa de Salud Pública a nivel nacional, que tuvo su inicio en 1979 con el cribado de la fenilcetonuria y es financiado totalmente por el Estado portugués. Se trata de un programa no obligatorio, con una tasa de cobertura del 99,8%, en el que hoy en día se criban veintiséis enfermedades, incluyendo metabolopatías, hipotiroidismo congénito y fibrosis quística. La toma de muestra se hace al 3er día de vida y el tratamiento de los neonatos afectos empieza en torno al 10º día. Todos los análisis están centralizados en un único laboratorio, que procesa aproximadamente 88.000 muestras al año. En los últimos cuarenta y un años se cribaron más de 3.800.000 neonatos y se detectaron 2.130 niños afectados, lo que es un indicador del impacto del programa en la población. Los desafíos futuros incluyen la búsqueda de nuevas estrategias para incrementar el valor del programa, donde se evalúen nuevas enfermedades a cribar y la optimización del cribado actual.

Amiodarone-induced thyrotoxicosis in a pediatric patient: A rare and demanding clinical case.

Thyroid dysfunction is one of the most common adverse effects of amiodarone therapy, ranging from subclinical changes to overt clinical thyrotoxicosis (AIT) and/or hypothyroidism. Due to its heterogeneity, AIT lasts as a defiant entity, leading to a thorny treatment course, particularly in pediatrics. AIT can be classified as either type 1, type 2 or mixed form based on its pathophysiology. Differentiating between the main AIT subtypes is quite relevant, since there is specific treatment for both, however, this distinction may be difficult in clinical practice. We describe a rare case of AIT in a pediatric patient, with an uncommon congenital cardiac malformation, that started amiodarone therapy due to paroxysmal supraventricular tachycardia. AIT was reported 26 months after drug onset, with a sudden and explosive emerging. This case highlights the current AIT management challenges on the highdemanding pediatric field pursuing, ultimately, an enhanced patient´s care.

Children with type 1 diabetes of early age at onset - immune and metabolic phenotypes.

Objectives We aimed to evaluate children with type 1 diabetes (T1D) with early age at onset (EAO) for clinical, immune and metabolic features in order to identify age-related disease phenotypes. Methods Comparative study of two groups of T1D children: EAO (≤5 years) and later age at onset (LAO; >5 years), regarding the presence of other autoimmune (AI) diseases, diabetes ketoacidosis and immunologic profile at onset and metabolic data 1 year after diagnosis. Statistical analysis was performed with significance set for p < 0.05. Results The study included 137 children (EAO = 52, mean age 3.6 ± 1.5 [mean ± standard deviation (SD)] and LAO = 85, mean age 10.4 ± 2.9). EAO was more associated with concomitant AI diseases (p = 0.032). Despite no differences in disease onset, EAO presented with lower C-peptide levels (p = 0.01) and higher absolute lymphocyte number (p < 0.0001), with an inverse correlation between these two variables (p = 0.028). Additionally, the EAO group had a higher frequency of serum detection of three antibodies (Abs) (p = 0.0008), specifically insulin Abs (p = 0.0001). One year after diagnosis, EAO had higher total daily insulin (TDI) dose (p = 0.008), despite similar hemoglobin A1c (HbA1c). Conclusions Our data show an association of EAO T1D with more AI diseases, higher number of Abs, lower initial insulin reservoir and higher insulin requirements 1 year after diagnosis. In this group, immune imbalance seems more evident and disease progression faster, probably reflecting distinct "immune environment" with different ages at disease onset. Further studies in the field of immunogenetics and immune tolerance are required, to improve patient stratification and find novel targets for therapeutic intervention.

CYP21A2 Gene Pathogenic Variants: A Multicenter Study on Genotype-Phenotype Correlation from a Portuguese Pediatric Cohort.

BACKGROUND: Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21OHD) is an autosomal recessive disorder characterized by 3 overlapping phenotypes: salt-wasting (SW), simple virilizing (SV), and non-classic (NC). We aimed at conducting a nationwide genotype description of the CAH pediatric patients and to establish their genotype-phenotype correlation. METHODS: CAH patients were recruited from Portuguese pediatric endocrinology centers and classified as SW, SV, or NC. Genetic analysis was performed by polymerase chain reaction (sequence specific primer, restriction fragment length polymorphism) or direct Sanger sequencing. Genotypes were categorized into 4 groups (0, A, B, and C), according to their predicted enzymatic activity. In each group, the expected phenotype was compared to the observed phenotype to assess the genotype-phenotype correlation. RESULTS: Our cohort comprises 212 unrelated pediatric CAH patients (29% SW, 11% SV, 60% NC). The most common pathogenic variant was p.(Val282Leu; 41.3% of the 424 alleles analyzed). The p.(Val282Leu) variant, together with c.293-13A/C>G, p.(Ile173Asn), p.(Leu308Thr), p.(Gln319*), and large deletions/conversions were responsible for 86.4% of the mutated alleles. Patients' stratification by disease subtype revealed that the most frequent pathogenic variants were c.293-13A/C>G in SW (31.1%), p.(Ile173Asn) in SV (46.9%), and p.(Val282Leu) in NC (69.5%). The most common genotype was homozygosity for p.(Val282Leu; 33.0%). Moreover, we found 2 novel variants: p.(Ile161Thr) and p.(Trp202Arg), in exons 4 and 5, respectively. The global genotype-phenotype correlation was 92.4%. Group B (associated with the SV form) showed the lowest genotype-phenotype correlation (80%). CONCLUSION: Our cohort has one of the largest NC CAH pediatric populations described. We emphasize the high frequency of the p.(Val282Leu) variant and the very high genotype-phenotype correlation observed.

Prepubertal gynaecomastia in a boy with Peutz-Jeghers syndrome: managing the aromatase overexpression.

Background Gynaecomastia, although rarely related to testicular tumours, in boys with Peutz-Jeghers syndrome (PJS) usually occurs due to large-cell calcifying Sertoli cell tumour (LCCSCT). Case presentation A 4-year-old boy, with a genetic diagnosis of PJS, presented gynaecomastia since the age of 2, associated with increased height velocity (HV). He exhibited bilateral breast enlargement (Tanner-B4) and a testicular volume of 4 mL. Testicular ultrasound revealed multifocal microcalcifications in both testicles. A laboratory evaluation showed undetectable gonadotrophins, testosterone and oestrogen and inhibin A of 4.6 pg/mL (0.9-1.7). The boy was subjected to therapy with anastrozole. In the last follow-up, 2 years after the start of therapy, he experienced a less tense Tanner-B2 and a decrease in HV; serum inhibin A had become negative. Conclusions This is one of the most precocious PJS-related gynaecomastia treated with aromatase inhibitors (AIs) reported in the literature. Oestrogen levels, although under the detection limit, may be sufficient to stimulate breast tissue/growth plates. Inhibin A is a good marker of LCCSCT and an indicator of response to AIs.

Immune cell and cytokine patterns in children with type 1 diabetes mellitus undergoing a remission phase: A longitudinal study.

OBJECTIVE: Type 1 diabetes (T1D) develops in distinct stages, before and after disease onset. Whether the natural course translates into different immunologic patterns is still uncertain. This study aimed at identifying peripheral immune patterns at key time-points, in T1D children undergoing remission phase. METHODS: Children with new-onset T1D and healthy age and gender-matched controls were recruited at a pediatric hospital. Peripheral blood samples were evaluated by flow cytometry at 3 longitudinal time-points: onset (T1), remission phase (T2) and established disease (T3). Cytokine levels were quantified by multiplex assay. Fasting C-peptide, HbA1c, and 25OHD were also measured. RESULTS: T1D children (n = 28; 10.0 ± 2.6 years) showed significant differences from controls in circulating neutrophils, T helper (Th)17 and natural killer (NK) cells, with relevant variations during disease progression. At onset, neutrophils, NK, Th17 and T cytotoxic (Tc)17 cells were decreased. As disease progressed, neutrophil counts recovered whereas NK counts remained low. Th17 and Tc17 cells behavior followed the neutrophil variation pattern. B-cells were lowest in the remission phase and regulatory T-cells significantly declined after remission. Two cytokine response profiles were identified. Low cytokine-responders showed higher circulating fasting C-peptide levels at onset and longer remission periods. C-peptide inversely correlated with pro-inflammatory and cytotoxic cells. CONCLUSIONS: Our data suggest an association between immune cells, cytokine patterns and metabolic counterparts. The dynamic changes of circulating immune cells during disease progression involve key innate and acquired immune cell types. This longitudinal picture of T1D progression may enable disease staging and patient stratification, essential for individualized treatment.

Cystic Fibrosis Newborn Screening in Portugal: PAP Value in Populations with Stringent Rules for Genetic Studies.

Newborn screening (NBS) for cystic fibrosis (CF) has been shown to be advantageous for children with CF, and has thus been included in most NBS programs using various algorithms. With this study, we intend to establish the most appropriate algorithm for CF-NBS in the Portuguese population, to determine the incidence, and to contribute to elucidating the genetic epidemiology of CF in Portugal. This was a nationwide three-year pilot study including 255,000 newborns (NB) that were also screened for congenital hypothyroidism (CH) and 24 other metabolic disorders included in the Portuguese screening program. Most samples were collected in local health centers spread all over the country, between the 3rd and 6th days of life. The algorithm tested includes immunoreactive trypsinogen (IRT) determination, pancreatitis associated protein (PAP) as a second tier, and genetic study for cases referred to specialized clinical centers. Thirty-four CF cases were confirmed positive, thus indicating an incidence of 1:7500 NB. The p.F508del mutation was found in 79% of the alleles. According to the results presented here, CF-NBS is recommended to be included in the Portuguese NBS panel with a small adjustment regarding the PAP cut-off, which we expect to contribute to the improvement of the CF-NBS performance. According to our results, this algorithm is a valuable alternative for CF-NBS in populations with stringent rules for genetic studies.

Pseudohypoparathyroidism type 1B - a rare cause of tetany: case report.

Pseudohypoparathyroidism (PHP) is a rare group of disorders characterised by end-organ resistance to the parathyroid hormone (PTH). A 16-year-old boy presented with a 2-year history of involuntary dystonic movements involving mainly the left hand, initially after writing and later during physical exercise. Serum calcium was 1.37 mmol/L (2.20-2.69), phosphate 2.1 mmol/L (0.8-1.45) and PTH 302 ng/L (12-88). CT scan of the head demonstrated multiple subcortical and diffuse basal ganglia calcifications. Genetic analysis confirmed a methylation defect in the GNAS cluster on chromosome 20q13.32 which established the diagnosis. Treatment with calcitriol and calcium carbonate led to complete remission of symptoms. Causes of hypocalcaemia should be considered in evaluating patients with movement disorders. The diagnosis of PHP-1B is challenging but the overall prognosis is excellent.

Diplopia, Convergent Strabismus, and Eye Abduction Palsy in a 12-Year-Old Boy with Autoimmune Thyroiditis.

Pseudotumor cerebri (PTC) is defined by clinical criteria of increased intracranial pressure, elevated intracranial pressure with normal cerebrospinal fluid (CSF) composition, and exclusion of other causes such tumors, vascular abnormalities, or infections. The association of PTC with levothyroxine (LT4) has been reported. A 12-year-old boy has been followed up for autoimmune thyroiditis under LT4. Family history was irrelevant for endocrine or autoimmune diseases. A TSH level of 4.43 µUI/mL (0.39-3.10) motivated a LT4 adjustment from 75 to 88 µg/day. Five weeks later, he developed horizontal diplopia, convergent strabismus with left eye abduction palsy, and papilledema. Laboratorial evaluation revealed elevated free thyroxine level (1.05 ng/dL [0.65-1.01]) and low TSH, without other alterations. Lumbar puncture was performed and CSF opening pressure was 24 cm H2O with normal composition. Blood and CSF cultures were sterile. Brain MRI was normal. LT4 was temporarily discontinued and progressive improvement was observed, with a normal fundoscopy at day 10 and reversion of diplopia one month later. LT4 was restarted at lower dose and gradually titrated. The boy is currently asymptomatic. This case discloses the potential role of LT4 in inducing PTC. Despite its rarity and unclear association, PTC must be seen as a potential complication of LT4, after excluding all other intracranial hypertension causes.

Metformin effectiveness and safety in the management of overweight/obese nondiabetic children and adolescents: metabolic benefits of the continuous exposure to metformin at 12 and 24 months.

INTRODUCTION: Childhood obesity prevalence is rising and new therapeutical approaches are needed. Metformin is likely beneficial in obese and/or insulin-resistant children/adolescents, but its role in this setting is still unclear. We aimed to evaluate the effectiveness, in terms of weight loss and insulin resistance, and safety of metformin in nondiabetic overweight/obese children and adolescents. METHODS: We retrospectively reviewed clinical records of 78 nondiabetic obese/overweight [body mass index (BMI)≥85th/95th percentile for age and sex] children and adolescents. Anthropometric and metabolic outcomes of 39 patients treated with metformin (mean daily dose: 1.3±0.5 g) were analyzed and compared to lifestyle intervention alone at different follow-up times (12 and 24 months). RESULTS: The mean age of the 78 patients was 13.3 years, 41 were females and mean BMI and BMI-SDS were 32.8 kg/m2 and 3.1, respectively. There was a decrease in mean BMI-SDS within each treatment group in all periods, except at 24 months for lifestyle intervention. However, the change in BMI-SDS was not significantly superior in the metformin group when compared to lifestyle intervention. Metformin had greater effectiveness over lifestyle intervention alone in reducing fasting insulin levels and homeostasis model assessment for insulin-resistance index (HOMA-IR) at both 12 and 24 months. Five patients had gastrointestinal adverse effects (12.8%), four requiring dose reduction, but metformin could be resumed in all. CONCLUSION: Metformin for nondiabetic obese/overweight children and adolescents resulted in a noteworthy insulin resistance improvement, without significant BMI advantage when compared to lifestyle intervention. Metformin metabolic and anthropometric effects appear to be beneficial up to 24 months, without relevant adverse effects, highlighting its potential long-term benefits.

[Hypothyroidism Associated to TSH Hormone-Receptor Autoantibodies with Blocking Activity Assessed In Vitro]. / Hipotiroidismo Associado a Anticorpos Anti-Receptor da Hormona TSH com Ação Bloqueadora Determinada In Vitro.

Thyroid-stimulating hormone-receptor autoantibodies normally causes hyperthyroidism. However, they might have blocking activity causing hypothyroidism. A 11-year-old girl followed due to type 1 diabetes mellitus, celiac disease and euthyroid lymphocytic thyroiditis at diagnosis. Two years after the initial evaluation, thyroid-stimulating hormone was suppressed with normal free T4; nine months later, a biochemical evolution to hypothyroidism with thyroid-stimulating hormone-receptor autoantibodies elevation was seen; the patient remained always asymptomatic. Chinese hamster ovary cells were transfected with the recombinant human thyroid-stimulating hormone -receptor, and then exposed to the patient's serum; it was estimated a 'moderate' blocking activity of these thyroid-stimulating hormone-receptor autoantibodies, and concomitantly excluded stimulating action. In this case, the acknowledgment of the blocking activity of the serum thyroid-stimulating hormone-receptor autoantibodies, supported the hypothesis of a multifactorial aetiology of the hypothyroidism, which in the absence of the in vitro tests, we would consider only as a consequence of the destructive process associated to lymphocytic thyroiditis.

Os anticorpos anti-receptor da hormona estimulante da tiróide causam habitualmente hipertiroidismo. No entanto, a sua atividade pode ser bloqueadora, condicionando o hipotiroidismo. Apresenta-se o caso de uma doente do sexo feminino, 11 anos, com diabetes mellitus tipo 1, doença celíaca e tiroidite linfocítica em eutiroidismo ao diagnóstico. Cerca de dois anos após a avaliação inicial, a hormona estimulante da tiróide apresentava-se suprimida com T4 livre normal. Nove meses depois, a evolução foi para hipotiroidismo notandose concomitantemente elevação dos anticorpos anti-receptor da hormona estimulante da tiróide, mantendo-se a doente sempre assintomática. Células chinese hamster ovary foram transfetadas com o receptor de hormona estimulante da tiróide, e após incubação com o soro da doente, verificou-se uma atividade bloqueadora âmoderadaâ dos anticorpos anti-receptor da hormona estimulante da tiróide, excluindo-se ação estimuladora concomitante. Neste caso, o reconhecimento da ação bloqueadora dos anticorpos anti-receptor da hormona estimulante da tiróide detetados no soro suporta a hipótese de uma etiologia multifatorial para o hipotiroidismo que, na ausência dos testes in vitro, tenderíamos a interpretar unicamente como sequela do processo destrutivo associado à tiroidite linfocítica.

Down syndrome, insulin-dependent diabetes mellitus and hyperthyroidism: a rare association.

The association between Down syndrome (DS) and autoimmune endocrinopathies is well established. These disorders become increasingly frequent as children grow older and the onset of one often predisposes to the development of others. However, there are few cases in the literature reporting the simultaneous onset of type 1 diabetes mellitus and hyperthyroidism in children with DS. We describe a case of an 8-year-old girl with DS who presented at the emergency department with hyperglycaemia and ketosis as a primary manifestation of type 1 diabetes mellitus. During the initial investigation, hyperthyroidism was detected, with thyroid-stimulating hormone<0.01 µUI/mL, positive antithyroid antibodies and an increase in thyroid gland on ultrasound. The authors present this case to underline the usefulness of monitoring thyroid function at the diagnosis of diabetes, even without apparent clinical manifestations, and to alert for the possibility of autoimmune endocrine dysfunction in children with DS.

Childhood obesity, thyroid function, and insulin resistance ­ is there a link? A longitudinal study.

BACKGROUND: Serum thyroid stimulating hormone (TSH) levels are frequently elevated in obese children and are most likely to be associated with insulin resistance. However, clinical relevance of this association remains unclear. OBJECTIVES: To assess the prevalence of hyperthyrotropinemia; to analyze the relationship between TSH and homeostasis model assessment - insulin resistance (HOMA-IR); and to verify whether TSH levels and HOMA-IR vary with weight loss in obese children. SUBJECTS AND METHODS: Retrospective longitudinal study with data from baseline and 1 year after lifestyle intervention in a pediatric obese group (344 children were recruited and 100 among them completed follow-up). For postintervention analysis, three groups were considered according to body mass index-standard deviation score (BMI-SDS) variations: ≤-0.5 (significant weight loss); 0.5-0 (weight loss); and >0 (weight gain). Statistical analysis was performed using SPSS 19.0®. RESULTS: The prevalence of increased TSH levels was 9.3%. At baseline TSH (p=0.007), fT4 (p=0.006), and HOMA-IR (p<0.001) were positively correlated to BMI-SDS (n=344). Weight reduction was verified in 67 out of 100 cases but significant loss was present in only 21 cases. Decreases in both TSH and BMI-SDS were independently associated with decreases in HOMA-IR (p=0.005 and p=0.016, respectively). There was no correlation between TSH and BMI-SDS variation. Significant decreases in the HOMA-IR (p=0.006) were only achieved in the significant weight loss group. CONCLUSIONS: The prevalence of hyperthyrotropinemia was lower than previously reported. However, cutoff values were adjusted to pubertal stage, suggesting an over report in other studies. Insulin resistance and TSH were positively correlated, independent of body status. Although weight loss was not associated with TSH variation, a decrease in TSH levels was independently associated with decreases in HOMA-IR.

Novel Mutation in the CASR Gene (p.Leu123Ser) in a Case of Autosomal Dominant Hypocalcemia.

Autosomal dominant hypocalcemia, caused by activating mutations of the calcium-sensing receptor (CASR) gene, is characterized by hypocalcemia with an inappropriately low concentration of parathyroid hormone (PTH). In this report, we describe the identification of a novel missense mutation in the CASR gene, in a boy with autosomal dominant hypocalcemia. Polymerase chain reaction (PCR)-single strand and DNA sequencing revealed a heterozygous mutation in CASR gene that causes a leucine substitution for serine at codon 123 (p.Leu123Ser). This mutation was absent in DNA from 50 control patients. In silico studies suggest that the identified variant was likely pathogenic. Sequencing analysis in the mother suggested mosaicism for the same variant, and she was clinically and biochemically unaffected. Clinical manifestations of the index case started with seizures at 14 months of age; cognitive impairment and several neuropsychological disabilities were noted during childhood. Extrapyramidal signs and basal ganglia calcification developed later, namely, hand tremor and rigidity at the age of 7 and 18 years, respectively. Laboratory analysis revealed hypocalcemia, hyperphosphatemia, and low-serum PTH with hypomagnesemia and mild hypercalciuria. After 2 years of treatment with calcium supplements and calcitriol, some brief periods of clinical improvement were reported; as well as an absence of nephrocalcinosis.

Hypovitaminosis D and severe hypocalcaemia: the rebirth of an old disease.

Vitamin D deficiency, once thought to be eradicated, is becoming a frequent occurence in children, caused mainly by dietary insufficiency. The classical manifestation is rickets, but in infants severe hypocalcaemia may present as stridor, tetany, seizures or, rarely, heart disease. Here, we describe four infants who presented with complications of severe hypocalcaemia secondary to nutritional vitamin D deficiency. (1) Female, 4 months old, several spasms. (2) Male, 8 days old, generalised tonic-clonic seizure. (3) Male, 9 months old, tetany. (4) Male, 4 months old, cardiogenic shock. The cases highlight the importance of child vitamin D supplementation from birth and throughout childhood. We also note that the vitamin D state should be evaluated by the 25(OH)-D value and not the 1,25(OH)2-D.