Biomedical subjects

Lidia Sava

Publications and source records attributed to Lidia Sava.

4 recordsLinked to original sources

PubMed2005

Risk factors for congenital hypothyroidism: results of a population case-control study (1997-2003).

OBJECTIVE: To identify risk factors for permanent and transient congenital hypothyroidism (CH). DESIGN: A population-based case-control study was carried out by using the network created in Italy for the National Register of Infants with CH. METHODS: Four controls were enrolled for each new CH infant; 173 cases and 690 controls were enrolled in 4 years. In order to distinguish among risk factors for permanent and transient CH, diagnosis was re-evaluated 3 years after enrollment when there was a suspicion of transient CH being present. Familial, maternal, neonatal and environmental influences were investigated. RESULTS: An increased risk for permanent CH was detected in twins by a multivariate analysis (odds ratio (OR) = 12.2, 95% confidence interval (CI): 2.4-62.3). A statistically significant association with additional birth defects, female gender and gestational age >40 weeks was also confirmed. Although not significant, an increased risk of CH was observed among infants with a family history of thyroid diseases among parents (OR = 1.9, 95% CI: 0.7-5.2). Maternal diabetes was also found to be slightly associated with permanent CH (OR = 15.7, 95% CI: 0.9-523) in infants who were large for gestational age. With regard to transient CH, intrauterine growth retardation and preterm delivery were independent risk factors for this form of CH. CONCLUSION: This study showed that many risk factors contribute to the aetiology of CH. In particular, our results suggested a multifactorial origin of CH in which genetic and environmental factors play a role in the development of the disease.

Adult↗

PubMed2003

Thyroid hemiagenesis: prevalence in normal children and effect on thyroid function.

Thyroid hemiagenesis prevalence was studied by neck ultrasound examination in 24,032 unselected 11- to 14-yr-old schoolchildren from southeastern Sicily. Twelve cases of thyroid hemiagenesis were identified, with a prevalence of 0.05%. The female to male ratio was 1:1.4. Thyroid hemiagenesis was always due to the absence (11 cases) or severe hypoplasia (1 case) of the left lobe. The hemiagenetic thyroid volume was within the normal total thyroid volume range normalized to age in 4 of 12 cases, enlarged in 3, and significantly reduced in 5. Thyroid function (thyroid hormones and TSH, both basal and 30 min after administration of 200 micro g TRH, iv) was evaluated in 9 of 12 children and was always within the normal range. However, children with thyroid hemiagenesis had an average serum TSH significantly higher than that of 18 matched controls (2.8 +/- 0.6 vs. 1.9 +/- 0.5 mU/liter; P < 0.001). This study confirms that thyroid hemiagenesis is nearly always due to left lobe defect, and that its prevalence is similar to the cumulative prevalence of thyroid agenesis and ectopia. Compensatory hypertrophy of the residual thyroid lobe occurs in most, but not all, cases and is due to thyroid tissue overstimulation by TSH. The high risk of goiter and hypothyroidism suggests systematic follow-up of all identified cases of thyroid hemiagenesis.

Adolescent↗

PubMed2002

Genetics of specific phenotypes of congenital hypothyroidism: a population-based approach.

Congenital hypothyroidism (CH) may cause severe and irreversible neurologic and developmental abnormalities when not recognized early. Many millions of newborns have now been screened and many thousands of patients with CH have been identified. Approximately 80%-85% have defects of thyroid gland development, while 15%-20% have congenital errors of thyroid hormone biosynthesis. An entire population screened for CH over a long period of time, was studied in the present report, using a population-based approach. In particular, two CH phenotypes, both presenting with in situ thyroid gland (patients with either goiter or with thyroid gland volume ranging from normal to hypoplasic) were analyzed. Mutations were searched in some of the most likely candidate genes: thyroperoxidase (TPO) in patients with CH goiter, Pax8 and thyrotropin receptor (TSHR) in the other group. In the former group (n = 8), four TPO gene mutations were identified in three patients. One patient was a compound heterozygous. In two cases an already described mutation (1277(insGGCC)) was present; in two other cases mutations not previously described (1996(G-->T) and 2295(G-->A)), which induced aminoacid variations with a Glu --> Stop and Val --> Ile changes, respectively, were identified. In all patients mutations were inherited from one of the parents. In the case of the compound heterozygous patient, one mutation was inherited from the mother (1277(insGGCC)) and the other from the father (1996(G-->T), Glu --> Stop). In the latter group (n = 8), a patient with a 16-base pair C(T)(13)CC deletion in TSHR gene intron 8, 42-bp distal to exon/intron 8 splice junction, was identified. No mutation was identified in Pax8 gene.

Congenital Hypothyroidism↗

PubMed2002

Subclinical hypothyroidism in early childhood: a frequent outcome of transient neonatal hyperthyrotropinemia.

Newborns with high TSH at birth and with normal free T(4) and normal or slightly elevated TSH at the confirmatory examination are considered false positive for congenital hypothyroidism. We evaluated thyroid function, thyroid antibodies, thyroid volume and morphology, thyroperoxidase and TSH receptor genes, and auxological data in 56 false positive children at 16-44 months of age. In these children thyroid function at confirmatory examination was fully normal in 33 (TSH, 0.8-4.9 mU/liter; group I) and nearly normal (borderline elevated TSH, 5.0-11.7 mU/liter) in the other 23 (group II). Compared with 65 control children with normal TSH at birth, false positive children had significantly higher basal serum TSH (mean +/- SD, 4.38 +/- 2.2 vs. 1.4 +/- 0.8 mU/liter; P < 0.01). Subclinical hypothyroidism, indicated by increased basal TSH and/or increased TSH response to TRH, was present in 36% children in group I and 70% in group II. Free T(4) was within the normal range in all children. Compared with the control group, false positive children had significantly higher free T(3) values (4.9 +/- 0.8 vs. 3.7 +/- 1.0 pmol/liter; P < 0.01) and a higher prevalence of antithyroid antibodies (25% vs. 1.5%; P < 0.001). Frequent thyroid morphology abnormalities and frequent thyroperoxidase and TSH receptor gene sequence variations were also observed. In conclusion, newborns classified false positive at congenital hypothyroidism screening have a very high risk of subclinical hypothyroidism in infancy and early childhood.

Aging↗