A population-based study on the frequency of additional congenital malformations in infants with congenital hypothyroidism: data from the Italian Registry for Congenital Hypothyroidism (1991-1998).

In the last decade a high frequency of other congenital anomalies has been reported in infants with congenital hypothyroidism (CH) detected by neonatal screening. In the present study the occurrence of additional congenital malformations (CM) in the population of CH infants detected in Italy between 1991 and 1998 (n = 1420) was investigated. In Italy all of the centers in charge of screening, treatment, and follow-up of CH adhere to the Italian National Registry of infants with CH. In this study a high prevalence of additional CM (8.4%), more than 4-fold higher than that reported in the Italian population (1-2%), was found in the population of CH infants. Cardiac anomalies represented the most frequent malformations associated with CH, with a prevalence of 5.5%. However, a significant association between CH and anomalies of nervous system, eyes, and multiple CM was also observed. In conclusion, the significantly higher frequency of extrathyroidal congenital malformations reported in the CH infants than in the general population represents a further argument supporting the role of a genetic component in the etiology of CH. Investigations of the molecular mechanisms underlying developmental events of formation of thyroid and other organs represent critical steps in the knowledge of CH etiology.

[Congenital forms of hypothyroidism: study of risk factors and preventive interventions]. / Forme congenite di ipotiroidismo: studio dei fattori di rischio e interventi di prevenzione. Gruppo di Studio per il Registro Nazionale degli Ipotiroidei Congeniti.

Maternal and child health represents one of the most relevant fields of interest in public health and particular attention is given to congenital pathologies. In Italy, the incidence of congenital hypothyroidism (CH) is 1:3200 live birth. CH is diagnosed at birth by neonatal thyroid screening. This allows a precocious onset of substitutive therapy which avoids severe psychomotor deficits in infants with CH. Moreover, the newborn screening program have permitted to identify transient disorders of thyroid function in newborns. These are essentially due to neonatal, maternal and environmental risk factors, especially iodine deficiency. The National Register (NR) of infants with CH was established in 1987. The aim of the NR is to provide disease surveillance and to monitor efficiency and effectiveness of neonatal screening. Furthermore, the NR represents an useful tool for developing epidemiological studies to identify possible environmental and/or familial risk factors of CH.

[Transient congenital hypothyroidism in iodine deficiency areas. Gruppo di Studio per il Registro Nazionale degli Ipotiroidei Congeniti]. / Ipotiroidismo congenito transitorio in aree iodocarenti. Gruppo di Studio per il Registro Nazionale degli Ipotiroidei Congeniti.

On the basis of data collected in the National Register of infants with congenital hypothyroidism (CH), a mean incidence of 1 case of CH to 3200 live births has been estimated in Italy. Nevertheless a higher incidence (> 1:2000) than national mean value has been observed in several districts of our country. The aim of this study was to verify a possible occurrence of transient hypothyroidism (TH) in these areas. Results of our study showed that the proportion of infants with thyroid in situ was significantly higher in the areas with very high CH incidence than in the remaining parts of the country. Also serum TSH levels at confirmation showed a less severe hypothyroidism in infants of these areas when compared with the other CH infants. Furthermore, preliminary results of diagnosis reevaluation showed 58% of TH in the areas with CH incidence > 1:2000. Lower percentages of TH have been observed in the other areas in relation to the decreasing of CH incidence. Most of the high CH incidence areas are historically affected by iodine deficiency. This observation supports the hypothesis that iodine deficiency can contribute to the occurrence of transient disorders of thyroid function in our population and stresses the need of promoting diffusion of an adequate iodine prophylaxis.

[Re-evaluation of the diagnosis in congenital hypothyroidism]. / La rivalutazione della diagnosi nell'ipotiroidismo congenito.

Newborn screening for congenital hypothyroidism (CH) has become routine in Italy. It provided new information regarding the epidemiology, diagnosis and treatment of CH infants and allowed to identify transient disorders of thyroid function in infancy. In fact, when the permanence of hypothyroidism has not been established in the newborn period, a confirmation of the diagnosis at 2-3 years of life should be performed. In this study results regarding the diagnosis reevaluation performed in 23 out of 184 CH children followed at the follow-up center for CH of the University of Rome "La Sapienza", are reported. Eleven of 23 reevaluated children had transient hypothyroidism (TH) and permanent CH was confirmed in the others. Four of the 11 TH children had law gestational age at birth, 1 had high antithyroid peroxidase titre due to maternal autoimmune thyroiditis and 2 were resident in iodine deficient areas. Our results show the importance of diagnosis reevaluation to identify transient disorders of thyroid function in infancy and confirm the role of neonatal, maternal and environmental factors in the etiopathogenesis of TH.

[Neonatal screening in congenital hypothyroidism in Italy. The National Registry]. / Lo screening neonatale dell'ipotiroidismo congenito in Italia. Il Registro Nazionale.

Neonatal screening for congenital hypothyroidism (CH) began in Italy in 1977 and then progressively developed covering 97% of live births in 1992. The National Register of infants with congenital hypothyroidism was established in 1987 as a project of the Health Ministry and is coordinated by the Italian Institute of Health. The aim of the Register is to provide disease surveillance, to monitor the efficiency and effectiveness of neonatal screening and to allow the identification of possible etiological risk factors in congenital hypothyroidism. The results of the Register provided valuable epidemiological informations about congenital hypothyroidism in Italy and evidenced several areas in whom an increased incidence probably caused by iodine deficiency was observed. Discussion of Register data during annual national meetings has allowed an improvement of the screening program with particular regard to the beginning of therapy with L-thyroxine and its dose. Because of the wide spectrum of collected information, the National Register represents a useful tool for developing of collaborative studies concerning some aspects of CH not yet completely elucidated.

Thyroid hypofunction related with the progression of human immunodeficiency virus infection.

Thyroid function was evaluated in 119 human immunodeficiency virus (HIV) infected patients at different stages of infection, compared with euthyroid normal subjects and hepatitis C virus infected blood donors as control groups. The low T3 state, well documented in severe nonthyroidal illnesses, was not found in these HIV infected patients. They showed lower FT4 levels and higher TSH and TBG values than euthyroid normal controls. These findings suggested a thyroid hypofunction becoming more evident with the progression of the infection as also supported by the presence of antithyroid autoantibodies mainly found in the symptomatic stages of the infection.

Endocrine response to HIV infection. Involvement of thyroid gland.

Endocrine dysfunctions were associated at different stages of infection, including those early in the course of HIV infection. In fact adrenal insufficiency, hyporeninemic hypoaldosteronism, hyponatremia, reduced gonadotropins levels, gonadal abnormalities and changes in hormone-binding proteins were reported in HIV infection. Also a thyroid involvement with autoimmune phenomena was observed in HIV infection by several studies giving different explanations of altered thyroid conditions. These findings suggest an effect of HIV on endocrine system. Recognition of endocrine manifestations in these patients may contribute to better characterize different stages of the infection and improve the management of HIV patients.

[National Register of congenital hypothyroidism]. / Il registro nazionale degli ipotiroidei congeniti.

The results of five years activity of the National Register of children with Congenital Hypothyroidism (NRCH) have been evaluated. NRCH was established in Italy in 1987, as a pilot project of Health Ministry. All Italian Centers in charge of the screening, treatment and follow-up of CH are involved in the program. The results have provided further epidemiological informations about CH in Italy and have evidenced some aspects in the screening organization which had to be improved. Discussion of Register data in annual meetings has recently allowed to obtain an improvement especially for the beginning of treatment and the used dose of therapy.

[Congenital hypothyroidism: organization and coordination of neonatal screening in Italy]. / Ipotiroidismo congenito: organizzazione e coordinamento dello screening neonatale in Italia.

Congenital hypothyroidism (IC) is the most frequent endocrine disease of the infancy and it is caused by primary deficiency of thyroid hormones. The damages derived by protracted hormone deficiency are diffused to all organs and systems and particularly severe for the development of central nervous system. Mental retardation can be prevented by early diagnosis and therapy. Early diagnosis is assured by neonatal thyroid screening performed on all newborns in the first days of life. The progress report on the screening situation in Italy as well as the national coordination realized in this field are presented.

Isoelectric focusing and immunoblotting analysis of thyroglobulin from different thyroid diseases.

Thyroglobulins (Tgs) have been obtained from macro-microfollicular goiter, toxic adenomas, papillary carcinomas and metastatic lympho-node and chromatographed by gel filtration. The 19S Tgs so obtained have been characterized by isoelectric focusing (IEF) and immunoblotting. IEF showed microheterogeneity pattern of Tgs from normal tissue, macro-microfollicular goiter and toxic adenomas to be within pH range from 4.2 to 4.5, while that from papillary carcinomas and metastatic lympho-node showed a wider microheterogeneity. Passive blotting of focused Tgs and immunoreaction with rabbit anti-Tg peroxidase conjugated antibody have been carried out and a positive reaction for all examined samples have been evidenced. Also two bands, focused at more cathodic pH value (pH 4.7), observed in IEF patterns of Tgs from carcinomas and metastatic lympho-node, gave a positive reaction with anti-Tg conjugated antibody. These differences observed in IEF and immunoblotting patterns of Tgs from papillary carcinomas and metastatic lympho-node are discussed in this report.

Three years of experience of the congenital hypothyroidism National Register.

Mental retardation caused by congenital deficiency of thyroid hormones can be prevented by early diagnosis and therapy which are assured by neonatal thyroid screening. Congenital hypothyroidism screening is performed in Italy by regional centres which in 1989 have screened more than 82% of neonatal population. Since 1987 a National Register of children affected by CH has been instituted. The results of the analysis of data collected in the first three years are reported.

Influence of environmental iodine deficiency on neonatal thyroid screening results.

During a multicentric pilot screening program for congenital hypothyroidism a comparison between the results obtained from Urbino, an area characterized by low iodine supply and endemic goiter, and Rome, a non-endemic area, has been made. The evaluation of neonatal urinary iodine excretion in the two areas showed significantly lower iodine urinary excretion levels in Urbino than in Rome. A shift of TSH at screening toward higher values as well as a higher percentage of recall in Urbino area than in Rome was observed. This finding, which well correlates with a low environmental iodine supply, emphasizes the importance of screening for congenital hypothyroidism as a suitable index of the presence and action of goitrogenic factors in the environment.

Longitudinal assessment of children with congenital hypothyroidism detected by neonatal screening.

Clinical and laboratory data from 42 children (31 females and 11 males) with primary congenital hypothyroidism (CH) diagnosed by neonatal screening over a six-year period are reported. The mean age at onset of thyroid hormone therapy was 33 days. The adequacy of replacement therapy was assessed by repeated TT4, FT4, T3 and TSH serum determinations. The high serum TT4 concentrations frequently observed were not accompanied by clinical evidence of hyperthyroidism. rT3 levels determined in 28 CH children with TT4 greater than 15 micrograms/dl were clearly higher than in the controls. The mean weight, length and head circumference remained always between the 50th and 75th centile. The radiological assessment of the knee, mainly the distal femoral surface, has been considered as an important clinical value in the initial diagnosis and in the evaluation of both severity and duration of disease. The psychomotor development was assessed using Brunet-Lezine's test until age 36 months, Stanford-Binet at 4 and 5 and WISC at 6 years of age. The mean global developmental quotients (GDQ) were always between 85 and 97 at 6 to 72 months of age, only eight children were below 85. A significant correlation was found between GDQ at 6 months and the bone age. The neurological examination showed an impairment of posture, coordination and subtle deficits in motor and perceptual abilities in a small percentage of children.