Fifteen Years of Iodine Prophylaxis in Italy: Results of a Nationwide Surveillance (Period 2015-2019)

CONTEXT

In 2005, a nationwide program of iodine prophylaxis on a voluntary basis was implemented in Italy by law. However, recent data on iodine status are lacking.

OBJECTIVE

The aim of this study was to evaluate efficiency, effectiveness, and possible adverse effects (increased occurrence of thyroid autoimmunity and hyperthyroidism) of the Italian iodine prophylaxis program.

METHODS

From 2015 to 2019, a nationwide survey was performed. The use of iodized salt was evaluated in a sample of 164 593 adults and in 998 school canteens. A sample of 4233 schoolchildren (aged 11-13 years) was recruited to assess urinary iodine concentration, prevalence of goiter, and thyroid hypoechogenicity on ultrasound, with the latter being an indirect indicator of thyroid autoimmunity. Neonatal TSH values of 197 677 infants screened in regions representative of Northern, Central, and Southern Italy were analyzed to investigate the percentage of TSH values >5.0 mIU/L. Data on methimazole prescriptions were analyzed as indirect indicators of new cases of hyperthyroidism.

RESULTS

The prevalence of the use of iodized salt was 71.5% in adult population and 78% in school canteens. A median urinary iodine concentration of 124 μg/L, a prevalence of goiter of 2.2%, and a prevalence of thyroid hypoechogenicity of 5.7% were observed in schoolchildren. The percentage of neonatal TSH values >5.0 mIU/L resulted still higher (5.1%) than the World Health Organization threshold of 3.0%, whereas the prescriptions of methimazole showed a reduction of 13.5%.

CONCLUSION

Fifteen years of iodine prophylaxis have led to iodine sufficiency in Italy, although there still is concern about iodine nutritional status during pregnancy.

A young boy with ventricular arrhythmias and thyroid dysgenesis: two genes are not enough?

Congenital hypothyroidism (CH) may be caused by biallelic variants in the TSHR gene. CH due to thyroid dysgenesis has also been linked to pathogenic variants of the nucleotide kinase 2, homeobox 5 (NKX2-5) gene, which can also cause sudden cardiac death from ventricular arrhythmia. In particular, the NKX2-5 p.Arg25Cys missense variant has been repeatedly reported in patients with congenital heart defects and, more rarely, with hypogonadism. We report the case of a 7 year old boy with ventricular arrhythmias, thyroid dysgenesis and intellectual disability, born from consanguineous Tunisian parents. Exome sequencing and segregation analysis revealed two potentially relevant variants: the NKX2-5 p.Arg25Cys variant (maternally inherited), as well as a single heterozygous TSHR p.Gln90Pro variant (paternally inherited). Of note, a male sibling of the proband, presenting with intellectual disability only, carried the same two variants. No other TSHR variants, or other potentially relevant variants were identified. In this proband, despite the identification of variants in two genes potentially correlated to the phenotype, a definite genetic diagnosis could not be reached. This case report highlights the complexity of exome data interpretation, especially when dealing with families presenting complex phenotypes and variable expression of clinical traits.

Expanded Newborn Screening in Italy Using Tandem Mass Spectrometry: Two Years of National Experience

Newborn screening (NBS) for inborn errors of metabolism is one of the most advanced tools for secondary prevention in medicine, as it allows early diagnosis and prompt treatment initiation. The expanded newborn screening was introduced in Italy between 2016 and 2017 (Law 167/2016; DM 13 October 2016; DPCM 12-1-2017). A total of 1,586,578 infants born in Italy were screened between January 2017 and December 2020. For this survey, we collected data from 15 Italian screening laboratories, focusing on the metabolic disorders identified by tandem mass spectrometry (MS/MS) based analysis between January 2019 and December 2020. Aminoacidemias were the most common inborn errors in Italy, and an equal percentage was observed in detecting organic acidemias and mitochondrial fatty acids beta-oxidation defects. Second-tier tests are widely used in most laboratories to reduce false positives. For example, second-tier tests for methylmalonic acid and homocysteine considerably improved the screening of CblC without increasing unnecessary recalls. Finally, the newborn screening allowed us to identify conditions that are mainly secondary to a maternal deficiency. We describe the goals reached since the introduction of the screening in Italy by exchanging knowledge and experiences among the laboratories.

Twenty Years of Neonatal Screening for Congenital Adrenal Hyperplasia in North-Eastern Italy: Role of Liquid Chromatography-Tandem Mass Spectrometry as a Second-Tier Test

BACKGROUND

Newborn screening for congenital adrenal hyperplasia (CAH) based on 17-hydroxyprogesterone (17-OHP) concentration in dried blood spots has been taking place in North-Eastern Italy since 2001. Since 2017, liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been introduced, for the first time in Italy, as a second-tier test.

AIMS

Our study aims to evaluate, on the one hand, the effectiveness of the newborn screening for CAH after 20 years of testing and, on the other, the impact that the introduction of the second-tier test had on the diagnostic accuracy of the screening program.

METHODS

Since 2001 dried blood spots taken from newborns have been screened with a time-resolved fluoroimmunoassay for 17-OHP determination. Over the years, the cut-off levels of 17-OHP were adjusted according to gestational age. Since 2017, a second-tier test in LC-MS/MS was introduced for samples displaying fluoroimmunoassay 17-OHP exceeding the cut-off.

RESULTS

In total, 862,521 newborns have been screened over a period of 20 years. The total incidence of 21-hydroxylase deficiency (21-OHD) was 1:25,368, moreover, a case of 11-β-hydroxylase deficiency was identified. All these diagnoses were genetically confirmed. The sensitivity and specificity of the screening program were 97% and 99.4%, respectively. The use of LC-MS/MS as a second-tier test significantly reduced the recall rate and increased the positive predictive value.

CONCLUSIONS

Screening for CAH is useful in the neonatal diagnosis of a classic form of 21-OHD, allowing a precocious treatment of affected children. The introduction of an LC-MS/MS second-tier reduced the recall rate, avoiding unnecessary blood withdrawal and medical evaluations and preventing stress to families. Furthermore, it helped identify rarer forms of CAH.

Newborn Screening for Biotinidase Deficiency. The Experience of a Regional Center in Italy

Introduction: Biotinidase deficiency (BD) is an autosomal recessive disease causing a defect in the biotin-releasing enzyme. Newborn screening (NBS) allows early diagnosis and treatment, ensuring excellent prognosis. The aim of this study was to describe our experience in the diagnosis, treatment, and follow-up showing key strategies and unsolved questions of the management of BD patients. Methods: We analyzed data of patients identified by the Regional Centre for Newborn Screening of Verona and followed by the Inherited Metabolic Disease Unit of Verona and Neonatal Intensive Care Unit of Bolzano, Italy, from 2014 to 2020. Results: Thirty-seven patients were diagnosed by NBS (five profound and 32 partial BD), with a total incidence of 1:5,996. All were started on biotin at diagnosis and presented no symptoms at follow-up. Analysis of parents and siblings led to identification of five asymptomatic patients with partial BD: one asymptomatic parent and four young siblings. Genetic analysis of the BTD gene identified 17 different genotypes and one mutation not previously known. Discussion: Our data confirm that NBS introduction had a dramatic impact on BD diagnosis, and the incidence has increased significantly compared to other areas. Partial defects are more common than profound and have a distinctive genotype. Partial BD treatment is still controversial even at what dose of biotin and for how long. At the end, BD treatment is very easy and inexpensive and prevents severe neurological damage. Sharing experiences is essential to achieving guidelines for treatment and follow-up and a better genotype-phenotype correlation.

Children with premature pubarche: is an alterated neonatal 17-Ohp screening test a predictive factor?

BACKGROUND

Neonatal screening for 21 hydroxylase deficiency is designed to detect classical form of congenital adrenal hyperplasia (CAH). It is still unclear whether newborns who result false positives at neonatal screening might later develop signs of androgen excess. The aim of this study is to verify whether a slightly elevated 17-OHP at newborn screening is a predictive factor for premature pubarche.

METHODS

We evaluated all infants born between 2001 and 2014 with premature pubarche. In case of increased bone age, they were submitted to functional tests to find out the cause of their symptoms. Their 17-OHP values at newborn screening for CAH were reconsidered.

RESULTS

We identified 330 patients (269 females, 61 males) with premature pubarche. All these children had a normal 17-OHP at newborn screening with the exception of a child, born preterm and not affected by CAH.

CONCLUSIONS

An elevated 17-OHP at newborn screening is not a predictive factor for premature pubarche. A likely cause of increased 17-OHP level at screening is an immaturity of adrenal gland or a neonatal stress. Therefore a strict follow up of these neonates during childhood is not necessary.

Congenital hypothyroidism with delayed TSH elevation in low-birth-weight infants: incidence, diagnosis and management

OBJECTIVE

To evaluate the incidence of congenital hypothyroidism (CH) with delayed TSH elevation among low-birth-weight (LBW) newborns in North-Eastern Italy and to verify if they need a second or third screening.

DESIGN

Analysis of clinical and biochemical data of newborns affected by CH with delayed TSH elevation identified by neonatal screening.

METHODS

Data of all newborns with birth weight (BW) <2500 g and evidence of delayed TSH elevation at newborn screening were collected between 2011 and 2014. Confirmatory tests were based on serum TSH and FT4 levels. All their clinical signs at diagnosis were reported.

RESULTS

57.5% of LBW newborns with delayed TSH increase at neonatal screening presented a CH with delayed TSH elevation and began a treatment with l-thyroxine. The incidence of this condition in North-Eastern Italy is therefore 1:908. The remaining infants presented a subclinical hypothyroidism (21.25%) or a complete normal serum thyroid function (21.25%). These data could be drawn only from a retesting strategy of neonatal screening.

CONCLUSIONS

Our report describes the incidence of CH with delayed TSH rise in North-Eastern Italy and differentiates this clinical condition from other thyroid dysfunctions of preterm or LBW newborns. The second-screening strategy for CH in neonates with BW < 2500 g proved useful in detecting newborns who otherwise would not be identified at the first screening.

Analysis of the d3-growth hormone receptor polymorphism in large cohorts of small, appropriate and large for gestational age newborns

BACKGROUND

Several studies evidenced a possible role of the d3-Growth Hormone Receptor (GHR) polymorphism in fetal growth. The GHR genotype distribution was studied in small (SGA) and appropriate (AGA) for gestational age newborns but never in the large (LGA) for gestational age babies. The aim of this study was to evaluate the frequencies of this polymorphism in a large cohort of SGA, AGA and LGA newborns.

METHODS

A total of 536 healthy newborns, randomly selected among the infants referred to the Italian North-Eastern centre for endocrinological and metabolic newborn screening, were enrolled: 192 SGA, 200 LGA and 144 AGA. Weight was recorded at birth. Isoforms of d3-GHR gene (fl/fl, d3/fl, and d3/d3) were analysed.

RESULTS

The analysis of the GHR genotype evidenced a lower frequency of the d3/d3 genotype in SGA cohort compared to the AGA population (P=0.005), or to the total population (P=0.035). No differences were found in the genotypic distribution between LGA and AGA population (P=0.373), or between LGA and the whole population (P=0.292).

CONCLUSIONS

d3/d3 GHR genotype was found twice as frequent in AGA and LGA cohorts compared to SGA subjects, whereas no significant differences in the frequency distribution of the GHR genotypes between LGA and AGA newborns were detected. The data leads to the exclusion of the GHR exon 3 deletion polymorphism as a possible genetic factor leading to LGA pregnancies.

Identification of a novel pax8 gene sequence variant in four members of the same family: from congenital hypothyroidism with thyroid hypoplasia to mild subclinical hypothyroidism

BACKGROUND

Congenital hypothyroidism is often secondary to thyroid dysgenesis, including thyroid agenesis, hypoplasia, ectopic thyroid tissue or cysts. Loss of function mutations in TSHR, PAX8, NKX2.1, NKX2.5 and FOXE1 genes are responsible for some forms of inherited congenital hypothyroidism, with or without hypoplastic thyroid. The aim of this study was to analyse the PAX8 gene sequence in several members of the same family in order to understand whether the variable phenotypic expression, ranging from congenital hypothyroidism with thyroid hypoplasia to mild subclinical hypothyroidism, could be associated to the genetic variant in the PAX8 gene, detected in the proband.

METHODS

We screened a hypothyroid child with thyroid hypoplasia for mutations in PAX8, TSHR, NKX2.1, NKX2.5 and FOXE1 genes. We studied the inheritance of the new variant R133W detected in the PAX8 gene in the proband's family, and we looked for the same substitution in 115 Caucasian European subjects and in 26 hypothyroid children. Functional studies were performed to assess the in vitro effect of the newly identified PAX8 gene variant.

RESULTS

A new heterozygous nucleotide substitution was detected in the PAX8 DNA-binding motif (c.397C/T, R133W) in the proband, affected by congenital hypothyroidism with thyroid hypoplasia, in his older sister, displaying a subclinical hypothyroidism associated with thyroid hypoplasia and thyroid nodules, in his father, affected by hypothyroidism with thyroid hypoplasia and thyroid nodules, and his first cousin as well, who revealed only a subclinical hypothyroidism. Functional studies of R133W-PAX8 in the HEK293 cells showed activation of the TG promoter comparable to the wild-type PAX8.

CONCLUSIONS

In vitro data do not prove that R133W-PAX8 is directly involved in the development of the thyroid phenotypes reported for family members carrying the substitution. However, it is reasonable to conceive that, in the cases of transcriptions factors, such as Pax8, which establish several interactions in different protein complexes, genetic variants could have an impact in vivo.

Genotype in the diagnosis of 21-hydroxylase deficiency: who should undergo CYP21A2 analysis?

AIMS

to confirm the diagnosis of 21-hydroxylase deficiency (21-OHD) by the analysis of CYP21A2 gene in infants with clinical and/or biochemical features of 21-OHD in order to clarify which patients to submit to genetic analysis; to analyze the genotype-phenotype concordance in these infants.

SUBJECTS AND METHODS

We studied 25 children with clinical and/or biochemical features of 21-OHD. All of them and their parents were submitted to genetic analysis of CYP21A2. Patients were classified in 3 groups according to mutations' severity: severe (group A), moderate (group B) or mild (group C).

RESULTS

CYP21A2 gene mutations were found in 17 children. Whereas all infants of groups A and B presented a classical form of 21- OHD, children of group C had a non-classical form of 21-OHD. Four infants resulted heterozygotes and 4 children were wildtype. A girl clinically presenting a non-classical form of 21-OHD resulted compound heterozygote with one of the mutations not described in literature (R25W) and whose residual enzymatic activity is not already known. All affected children presented a 17-OHP level after ACTH stimulation greater than 100 nmol/l. We found an optimal concordance between 17-OHP levels after ACTH test and genotype.

CONCLUSIONS

CYP21A2 analysis permitted to confirm the diagnosis of 21-OHD in 68% of our children. To improve this percentage we suggest to perform the CYP21A2 analysis only when 17-OHP after ACTH test is greater than 100 nmol/l. Moreover, we found an optimal genotype-phenotype concordance in the 21-OHD patients.

3-hydroxyacyl-coenzyme a dehydrogenase deficiency: identification of a new mutation causing hyperinsulinemic hypoketotic hypoglycemia, altered organic acids and acylcarnitines concentrations

The human HADH gene encodes the short-chain-L-3-hydroxyacyl-CoA dehydrogenase, the enzyme which catalyzes the third step of the β-oxidation of the fatty acids in the mitochondrial matrix. Loss-of-function mutations in the HADH gene lead to short-chain-L-3-hydroxyacyl-CoA dehydrogenase deficiency, an autosomal recessive genetic defect of unknown prevalence with a wide spectrum of phenotypic variability. As in other metabolic diseases, the diagnostic relevance of the biochemical evaluations, plasma acylcarnitines, and urinary organic acids, are crucially dependent on the clinical conditions of the patient during specimen collection.This paper describes the eighth patient carrying a HADH gene mutation, a new homozygous deletion c.565delG leading to an early stop codon (p.V116Wfs124X), in an infant with hyperinsulininemic hypoglycemia, displaying abnormal patterns of plasma acylcarnitines and urinary organic acids. We conclude that, when the residual catalytic activity of the mutated enzyme is seriously reduced, the biochemical hallmarks of the disease, namely plasma 3-hydroxybutyrylcarnitine and urinary 3-hydroxyglutaric acid, are invariably present.

[Influence of thyroid morphology on psychomotor development in patients with congenital hypothyroidism during 8 year follow-up]

AIM

The aim of this paper was to evaluate the impact of thyroid morphology on auxological and neuropsychological development in children affected by congenital hypothyroidism (CH), treated with levothyroxine, up to 8 years of age.

METHODS

Fifty-three children affected by CH divided into 3 groups on the basis of thyroid morphology determined at birth: patients with athyreosis (N=17), with ectopic gland (N=23), with in situ thyroid (N=13). The developmental quotient (DQ) was evaluated by the Brunet-Lezine test up to 3 years, and intelligent quotient (IQ) by the Terman-Merril test after 3 years of age.

RESULTS

DQs at one year in athyreotic patients are lower (P<0,05) as compared to those determined in patients with other thyroid morphology. Later on these patients still showed lower DQ and IQ values than in other groups, although statistically not significant.

CONCLUSION

Thyroid morphology seems to be fundamental in psychomotor development, in fact patients with athyreosis show a transient impairment at one year of age. This difference could be transient or to have repercussions on adult. Individualization of the starting dose of levothyroxine on the basis of thyroid morphology, could be useful.

Subclinical hypothyroidism in children and adolescents: a wide range of clinical, biochemical, and genetic factors involved

OBJECTIVE

The aim of the study was to examine clinical characteristics, biochemical parameters, and TSH-R gene variations in children and adolescents with subclinical hypothyroidism (SH) in order to evaluate their pattern of distribution in SH.

PATIENTS

We enrolled 88 patients, each having at least two TSH measurements above the upper limit of the reference range with normal free thyroid hormones and negative thyroid autoantibodies.

MAIN OUTCOME MEASURES

Clinical characteristics included height, weight, family history of thyroid diseases, thyroid volume, and echogenicity at ultrasonography. Biochemical parameters included TSH, free thyroid hormones, thyroid autoantibodies, and adjusted daily urinary iodine excretion (UIE). Genetic variations in the TSH-R gene were assessed.

RESULTS

The prevalence of overweight/obesity, positive family history of thyroid diseases, and thyroid hypoechogenicity was 28.4, 45.5, and 22.7%, respectively. Median TSH was higher in overweight/obese patients than in normal-weight ones (7.4 vs. 5.7 muIU/ml; P = 0.04) and in overweight/obese patients with hypoechogenicity than in those with normal ultrasound pattern (8.5 vs. 6.8 muIU/ml; P = 0.04). Adjusted daily UIE was lower in subjects without than in those with a positive family history of thyroid diseases (81 vs. 120 mug/d; P = 0.001). The prevalence of a positive family history of thyroid diseases was 1.9-fold higher in patients with nonsynonymous mutations in the TSH-R gene than in patients without any mutation (80 vs. 42%; P = 0.03). A novel mutation at position 1559 in exon 10 (W520X) was detected in one child.

CONCLUSIONS

Overweight/obesity, thyroid hypoechogenicity, and nonsynonymous mutations in the TSH-R gene are characterizing features of a large portion of SH children.

Functional studies of new TSH receptor (TSHr) mutations identified in patients affected by hypothyroidism or isolated hyperthyrotrophinaemia

OBJECTIVES

To establish the role of new TSH receptor (TSHr) variants (P27T, E34 K, R46P, D403N, W488R and M527T) recently identified in children with congenital hypothyroidism (CH) or subclinical hypothyroidism (SH) with a thyroid gland of normal size.

DESIGN AND MEASUREMENTS

TSHr variants were obtained by mutagenesis. Wild-type (wt) and TSHr mutants were expressed in COS cells and cAMP assay, (125)I-TSH binding and microchip flow cytometry analyses were performed.

RESULTS

D403N and M527T mutants showed a lower cAMP response to bovine TSH (bTSH) with respect to the wtTSHr. R46P and W488R mutants did not show any response to bTSH stimulation in terms of cAMP production. The E34 K mutant showed a significantly lower cAMP response to stimulation with bTSH, while P27T had a lower cAMP response only to the highest dose of bTSH used. P27T, E34 K, D403N and M527T mutants showed a lower TSH binding capacity with respect to the wtTSHr. R46P and W488R mutants did not show any TSH binding.

CONCLUSIONS

E34 K, D403N, M527T, R46P and W488R TSHr variants seem to cause a functional abnormality of the receptor which is responsible for the observed phenotype. The P27T TSHr variant does not seem to play a functional role in the pathogenesis of CH and should be considered as a polymorphism.

A technique of mRNA extraction and labeling from circulating lymphocytes of children treated with growth hormone replacement therapy for microarray analysis

GH replacement therapy exhibits a wide spectrum of response in terms of growth. Nevertheless, standardized doses are still given in clinical practice. In order to optimize the therapy, it is necessary to identify its markers of responsiveness. Given the presence of GH receptors in the circulating lymphocytes, accessible by means of a simple blood withdrawal, blood becomes the tissue of choice as a source of RNA for in vivo gene expression analysis. Hence, the purpose of the present paper is to develop a method of preparation of RNA from lymphocytes suitable for microarray analysis, focusing on the reduction of the blood volume withdrawal in order to perform the analysis on pediatric subjects. After lymphocyte isolation and total RNA extraction from 6 ml of blood, we carried out an amplification procedure preserving the relative abundance of each transcript. Thereafter, we hybridized the labeled amplified RNA on an oligo chip (Human 30K A, MWGBiotech), but the unsuccessful detection of a good signal to noise ratio indicates that labeled RNA is still insufficient. Therefore, we suggest performing pools of total RNA from different subjects with similar responsiveness to the therapy. It can be speculated that, upon comparison of the obtained data with those derived from pools of controls properly responding to the therapy, specific hallmarks of the condition of low responsiveness, devoid of inter-individual variability, will be evidenced.

Lack of association between thyrotropin receptor gene polymorphisms and subclinical hypothyroidism in children

Subclinical hypothyroidism is defined as a serum TSH level above the statistically set reference range, associated to normal free thyroid hormone concentrations. Genetic and environmental factors contribute to the inter- and intra-individual biological variations of TSH levels, sometimes leading to uncertainty of treatment in the clinical practice, especially when moderate elevations above the upper limit of the reference range are considered (5< TSH <10 mIU/l). In this view, the study of association between subclinical hypothyroidism and possible molecular effectors, such as polymorphisms in the TSH receptor (TSHR) gene, could be interesting. In this paper, we analyzed the TSHR gene polymorphisms in 103 hyperthyrotropinemic infants. A control group of 120 newborns of the same ethnic background was used to evaluate the frequencies of each polymorphism in the population. We found a statistically significant difference in the allelic frequency of the P52T polymorphism, being that the T variant was more represented in the control group (p=0.03). However, no significant results have been obtained in the analysis of the association between genotypes and serum TSH levels. In conclusion, we analyzed 7 polymorphic variants of TSHR gene in subclinical hypothyroidism. The only significant result refers to the allelic frequency of A in the P52T polymorphism, which is statistically reduced when compared with that of a control group.

Thyrotropin receptor gene mutations and TSH resistance: variable expressivity in the heterozygotes

OBJECTIVE

TSH resistance ranges from overt nonautoimmune hypothyroidism to subclinical hypothyroidism, defined as mild hyperthyrotrophinaemia but a euthyroid state clinically. To date, 23 inactivating mutations of the TSH receptor (TSHR) gene have been proven responsible for the clinical condition, but an absence of mutations in the TSHR gene has been reported for several cases of TSH resistance as well. In this paper, we aimed to investigate the actual role of the TSHR gene in the development of both subclinical and congenital hypothyroidism.

PATIENTS

14 hypothyroid newborns, 116 subclinical hypothyroid subjects and 120 healthy controls.

MEASUREMENTS

Through denaturing high performance liquid chromatography (DHPLC), we screened for mutations the TSHR gene (the proximal promoter, the exons and their flanking regions), and evaluated the association between serum TSH and functionally characterized alleles identified.

RESULTS

In the hypothyroid patients, one patient was heterozygous for a new missense variation, E34K, whereas two others patients were either homozygous or heterozygous for the P162A substitution. In the subclinical hypothyroid subjects, we detected only heterozygous substitutions: they are mostly new (123-124insTGCA, P27T, R46P, 555-561delTATTCTT, D403N, W488R, M527T), while six correspond to already published mutations (P162A, R109Q, L252P and three C41S). We only focused on those mutations that had been functionally characterized in vitro, and in whom serum TSH was available from family members.

CONCLUSIONS

A single grossly mutated allele (such as C41S or 555-561del) invariably leads to a condition of subclinical hypothyroidism, whereas in case of heterozygous carriers of mutations partially affecting the receptor function (such as P162A or L252P), a remarkable variable expressivity was detected among individuals belonging to different generations.

Neonatal Screening for Congenital Adrenal Hyperplasia in North-Eastern Italy: A Report Three Years into the Program

AIMS

To evaluate the incidence of congenital adrenal hyperplasia (CAH) in the Northern Italian population and the efficiency of the North-Eastern Italy screening program. To adjust cut-off levels for 17-hydroxyprogesterone (17-OHP) in relation to gestational age and birth weight, comparing the benefits in terms of reduction of recall rates with the two approaches and ultimately choosing the better of the two.

SUBJECTS AND METHODS

Since September 2001, blood samples from neonates born in North-Eastern Italy have been screened with a fluoroimmunoassay method for 17-OHP determination (DELFIA). A preliminary cut-off level of > or = 30 nmol/l was set both for term and preterm newborns. The values of 17-OHP were analysed using statistical methods in relation to gestational age and birth weight in order to modify the cut-off on the basis of our data.

RESULTS

After 33 months of screening we screened 128,282 newborns and detected 6 affected babies. During the first 8 months of screening among the recalled babies, 89.6 and 78.1% were preterm and low-birth-weight newborns, respectively, with a recall rate of 2.59% for premature neonates and of 4.94% for babies with birth weights < 2,500 g. We chose a new cut-off value of 50 nmol/l for preterm newborns only and, after 4 months, the recall rate was reduced to 0.83% for these infants and to 1.83% for low-birth-weight infants.

CONCLUSION

After 33 months of screening for CAH in North-Eastern Italy, we report an incidence of 1:21,380. In 5 out of 6 affected babies, the diagnosis was established only after a positive screening test, which prevented a severe salt-wasting crisis in these babies. The cut-off level related to gestational age led to a significant reduction in the number of false-positives among preterm babies.We therefore intend to continue with the screening program for CAH in North-Eastern Italy, keeping a gestational-age-related cut-off in the hope that our data may encourage a national screening program for CAH.