BACKGROUND: The intellectual outcome in children with congenital hypothyroidism detected by neonatal screening is generally good; however, subtle neurological dysfunctions, subnormal IQ, or both, have been reported. OBJECTIVE: To evaluate the intellectual outcome in 12-year-old patients with congenital hypothyroidism, detected by neonatal screening, in an attempt to identify factors that may affect intellectual development. METHODS: The intelligence quotient (IQ) of 40 children with congenital hypothyroidism was evaluated at 12 years of age, using the Wechsler Intelligence Scale for Children -- Revised, and compared with the IQ of 40 healthy siblings (control group). RESULTS: The mean IQ score (88.4+/-13.1) was not significantly different from that of the control group (93.4+/-10.7). Thirteen patients showed subnormal IQ score (72.4+/-4.9) compared with their siblings (86.7+/-9.6; P<0.0001) and with the other patients (96.1+/-9.6; P<0.0001). The low IQ score was associated with lower serum concentrations of thyroxine at diagnosis, poor treatment compliance during follow-up and lower familial IQ. Interviews with parents of children with congenital hypothyroidism revealed that a refusal to acknowledge the disease was linked to poor attention to the child's emotional life and to poor treatment compliance in some cases (11%). CONCLUSION: Even though the mean IQ score in patients with congenital hypothyroidism falls within normal for the control population, low IQ scores may be present in patients with severe hypothyroidism, inadequate compliance to replacement therapy during follow-up and poor parental pedagogic attitude.
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M Salerno, R Militerni, S Di Maio, C Bravaccio, N Gasparini, and A Tenore
DR Mann, MA Akinbami, KG Gould, and VD Castracane
OBJECTIVE: Neonatal treatment of male monkeys with a gonadotropin-releasing hormone antagonist (Ant) increased the incidence of delayed puberty. Using blood samples that had been collected from monkeys with normal or delayed puberty, we assessed the potential involvement of leptin and thyroxine (T4) in sexual development. DESIGN AND METHODS: Monkeys were treated from birth until 4 months of age with vehicle, Ant or Ant/androgen and blood samples were drawn from 10 to 62 months of age. RESULTS: Serum leptin and total T4 concentrations declined in parallel throughout adolescence in all treatment groups. There was no transient rise in leptin before or in association with the onset of puberty. Also, leptin did not differ during the peripubertal period between animals experiencing puberty at that time versus those in which puberty was being delayed. Neonates treated with Ant either alone or with androgen replacement had higher leptin levels than controls throughout development. While leptin exhibited no significant changes during the peripubertal period, T4 values increased and declined in parallel with the peripubertal changes in hypothalamic-pituitary-testicular activity. CONCLUSIONS: These data do not support the concept that a transient rise in leptin triggers the onset of puberty in male monkeys. However, the disruption of neonatal activity of the pituitary-testicular axis alters the developmental pattern of leptin. The changes in T4 levels during the peripubertal period suggest that thyroid status may be a significant contributor to the process of sexual development in the male monkey and that peripubertal changes in secretion of this hormone may serve as an effective physiological response during a critical period of elevated energy expenditure.
ML Hartoft-Nielsen, AK Rasmussen, A Kaas, U Feldt-Rasmussen, and K Buschard
OBJECTIVE: Changes in the functional state of beta cells by neonatal stimulation or adolescent suppression have reduced the incidence of type 1 diabetes mellitus in animal models. The aim of this study was to evaluate the effect of manipulation of the activity of the thyroid gland by neonatal stimulation or by adolescent suppression on the prevalence of spontaneous autoimmune thyroiditis (AIT) in rats. METHODS: Bio-Breeding/Worcester (BB) rats were treated neonatally with sodium iodine (NaI) or thyroid stimulating hormone (TSH), or during adolescence by triiodothyronine (T(3)), and the lymphocytic infiltration in the thyroid gland was evaluated. RESULTS: Neonatal treatment with NaI decreased the prevalence of AIT to 32+/-9% compared with 66+/-5% in the controls (P<0.002), mainly caused by a reduction among the female rats (13+/-9% vs 52+/-8%, P<0.006). TSH had no effect. Post neonatal suppression of the thyroid gland by T(3) had a biphasic response. Early in adolescence the overall prevalence was 14+/-7% compared with 66+/-5% in the controls (P<10(-5)); for female rats AIT was prevented (0+/-0%) compared with 52+/-8% in the controls (P<0.0003) and in male rats the values were 29+/-13% compared with 80+/-6% in the controls (P<0.001). Treatment with T(3) later in adolescence increased the overall prevalence to 81+/-7% compared with 66+/-5% in the controls (not significant). For female rats the prevalence increased to 78+/-9% compared with 52+/-8% in the controls (P=0.04). The degree of thyroiditis among the affected animals was similar in all groups. CONCLUSION: Neonatal stimulation of the thyroid gland by iodine or early adolescent suppression by T(3) reduced the prevalence of AIT whereas T(3) given later increased the prevalence of thyroiditis in rats. Thyroid activity at various ages seems to be of importance for the development of autoimmune thyroiditis.
LA Metherell, MO Savage, M Dattani, J Walker, PE Clayton, IS Farooqi, and AJ Clark
OBJECTIVE: Congenital isolated ACTH deficiency (IAD) is a rare inherited disorder that is clinically and genetically heterogeneous. Patients are characterised by low or absent cortisol production secondary to low plasma ACTH despite normal secretion of other pituitary hormones and the absence of structural pituitary defects. Onset may occur in the neonatal period, but may first be observed in later childhood. Recently, mutations in the TPIT gene, a T-box factor selectively expressed in developing corticotroph cells, have been found in cases of early-onset IAD. DESIGN: Here we report the screening of the TPIT gene in seven patients with IAD, four of whom had neonatal onset. METHODS: Genomic DNA was extracted and the sequences of the 8 TPIT exons and their intron/exon junctions were determined by automated sequencing. RESULTS: Two siblings with early-onset IAD were both compound heterozygotes for mutations in exons 2 and 6. The missense mutation (Met86Arg) in exon 2 within the T-box (or DNA binding domain) is predicted to disrupt DNA binding. A frameshift mutation in exon 6 (782delA) introduces a premature stop codon and is likely to lead to a non-functional truncated protein. No nucleotide changes were observed in exonic sequences in the other two early- or the three later-onset cases. Fifteen single nucleotide polymorphisms that were not predicted to change the TPIT transcript were also detected. CONCLUSIONS: These findings provide a further illustration of the genetic heterogeneity of IAD and are highly suggestive of one or more other genes being implicated in this disorder.
M Salerno, T Lettiero, A Esposito-Del Puente, V Esposito, D Capalbo, A Carpinelli, S Padula, and A Del Puente
OBJECTIVE: To evaluate whether long-term l-thyroxine therapy in young adults with congenital hypothyroidism may affect bone mineral density (BMD). DESIGN: Thirty-seven subjects with congenital hypothyroidism, detected by neonatal screening and longitudinally followed from the time of diagnosis and treatment (26+/-4 days) up to the age of 17.8+/-1.0 years, were studied. METHODS: Spinal (L2-L4) BMD, measured by dual-energy X-ray densitometry, and bone quality, measured as amplitude-dependent speed of sound (Ad-SoS) by quantitative ultrasound, were evaluated. RESULTS: Z-score mean values (+/-s.d.) of BMD (-0.3+/-0.7) and Ad-SoS (-0.7+/-1. 1) were slightly below the average but within the normal range. Ad-SoS resulted in a z-score below -1 in 38% of patients as compared with BMD which resulted in a z-score below -1 in only 13.5% of subject. No significant differences were observed between males (BMD, -0.3+/-0.7; Ad-SoS, -0.9+/-1.0) and females (BMD, -0.3+/-0.7; Ad-SoS, -0.5+/-1.2) or when dividing patients on the basis of aetiological defects; ectopic gland (BMD, -0.3+/-0.6; Ad-SoS, -0.8+/-0.9), athyreosis (BMD, -0.3+/-0.9; Ad-SoS, -0.8+/-1.0) and eutopic gland (BMD, -0.3+/-0.8; Ad-SoS, -0.4+/-1.3). No significant relationships were observed between BMD or Ad-SoS z-score and hormonal status or l-thyroxine dosages at the time of the study or during the pubertal period. CONCLUSIONS: The careful monitoring of serum thyroid-stimulating hormone and adjustment of l-thyroxine dosage avoided the significant deleterious effects of prolonged l-thyroxine replacement therapy on bone tissue in adolescents and young adults with congenital hypothyroidism treated from the neonatal period.
Stefania Bargagna, Luca Chiovato, Daniela Dinetti, Lucia Montanelli, Cristina Giachetti, Elisabetta Romolini, Mara Marcheschi, and Aldo Pinchera
Abstract
Objective: Neonatal screening for congenital hypothyroidism (CH) prevents the serious neuropsychological features of CH, but the question remains whether intelligence and motor skills of CH children treated early are completely normal.
Design: In this report we describe the rare case of two genetically identical twins, only one of whom was affected by CH due to thyroid agenesis. L-Thyroxine (9 μg/kg body weight/day) therapy was initiated at 27 days of age and was adequate throughout the follow-up.
Methods: Neuropsychological evaluation was performed on the twins in parallel from 3 months to 8 years of age.
Results: The CH twin (NB) did not show major neuromotor impairments but, compared with the unaffected twin (EB), she had a slight delay in postural/motor achievements and in language development that completely disappeared at 8 years of age. On standardised tests of intelligence, NB was indistinguishable from control children but, compared with her twin, she had lower IQ scores in most testing occasions up to 7 years of age (NB = 108 vs EB = 115). School achievements of NB did not significantly differ from those of her classmates but, compared with her twin, she scored worse in writing, mechanical reading, verbal memory, and possibly in arithmetic.
Conclusions: Because the twins were genetically and phenotypically identical, were raised in the same environment, and received a similar education, it is concluded that hypothyroidism in utero and in the first neonatal month was responsible for the lower neuropsychological achievements of the CH twin. While foetal hypothyroidism is at present unavoidable, earlier diagnosis and initiation of treatment in neonates with CH are important and highly recommended.
European Journal of Endocrinology 136 100–104
S Bargagna, D Dinetti, A Pinchera, M Marcheschi, L Montanelli, S Presciuttini, and L Chiovato
OBJECTIVE: Evaluation of school attainments in children with congenital hypothyroidism (CH) detected by neonatal screening and treated early in life. PATIENTS AND METHODS: Text comprehension, mathematics, reading, writing and verbal and spatial memory, as indices of school learning, were evaluated in nineteen 5- to 10-year-old children with CH attending nursery or elementary school. l-Thyroxine substitution (starting dose 8-10 microg/kg body weight per day) was initiated at a mean age of 30+/-10 days of life. The control group included 298 unaffected children matched with the CH children for age and school grade. Thirty per cent of controls were classmates of CH children. Intelligence quotients (IQ), language performances and motor development were evaluated in CH children at age 5 years, and were related to their school attainments. School performances of CH children were also compared with their neonatal serum thyroxine (T4) concentration, and with the social-cultural level of the family. RESULTS: Four out of 19 (21%) children with CH, 3 in the nursery and 1 in the elementary school, displayed a generalized learning disorder. Symbol copy, geometric copy, phrase repetition, dictation writing and spontaneous writing were particularly defective in nursery school CH children, while orthographic error recognition was defective in elementary school CH children. School learning disorders in CH children were significantly correlated with a borderline-low IQ, poor language performances and a low social-cultural level of the family, but not with motor skills or neonatal T4 concentration. CONCLUSION: School attainments of early treated CH children were within the normal range in most affected cases. However, about 20% of CH children, most of them attending nursery school, showed a generalized learning disorder. Low IQ scores and poor language performances at age 5 years were associated with defective learning, mainly in CH children living in a poor social-cultural environment. In this subset of CH children, prompt initiation of speech and psychomotor rehabilitation therapy is recommended in order to prevent subsequent school learning disorders.
Susan M. Scott, Carmela Guardian, Cathy Rogers, Pam Angelus, and Sher Werner
Abstract.
We have previously demonstrated that changes in urinary epidermal growth factor/creatinine ratios relate to gestational age and gender. It is unclear what controls this developmental pattern although chronic renal disease and thyroid aberrations have significant effects on epidermal growth factor and creatinine excretion in childhood and in adults. Therefore, we chose to explore the effects of these disease states on epidermal growth factor excretion during the perinatal time period. We collected urine samples from 8 infants with congenital renal disease and 45 infants with low T4 and normal TSH values who 'failed' the newborn screen. In addition, 2 infants with hypothyroidism and 2 infants with neonatal Grave's disease had urine samples examined. Values were compared with the epidermal growth factor and creatinine excretion from 190 infants. We demonstrated that epidermal growth factor excretion increased earlier in gestation than does creatinine excretion. In infants with renal disease or hypothyroidism, epidermal growth factor excretion was decreased while hyperthyroidism enhanced excretion. Epidermal growth factor excretion increased with relief of an obstruction but still remained low and creatinine excretion was unchanged. We confirm that in preterm infants as in childhood there are similar effects of thyroid and renal diseases on epidermal growth factor excretion.
Paul van Trotsenburg, Thomas Vulsma, André M. Bloot, Reindert D. Van der Gaag, Jan Willem Lens, Hemmo A. Drexhage, and JanJ. de Vijlder
Abstract.
Antibodies against the so called 'second colloid antigen' (CA2 antibodies) occurred in 51% of the mothers of hypothyroid children detected by screening for neonatal congenital hypothyroidism in Quebec (N = 49) and in The Netherlands (N = 26). In The Netherlands where corresponding neonatal serum was available, 31% (8 of 26) of the infants with congenital hypothyroidism were positive for antibodies against the second colloid antigen. When during follow-up, 3 to 5 years after diagnosis, the mothers and their children were investigated, 46% (7 of 15) of the mothers were positive for antibodies against the second colloid antigen, whereas 29% (4 of 14) of the hypothyroid children were also positive. Various control groups did not show more than a 12% positivity. This presence of thyroid-reactive antibodies in a proportion of the hypothyroid children 3 to 5 years after diagnosis is not compatible with a mere transplacental passage; it indicates that the antibodies must be produced by the mothers and by the children themselves. We conclude that a thyroid autoimmune response occurs in a considerable part of infants with congenital hypothyroidism and their mothers and that this immune response seems to persist in both of them for years.
Y. Rakover, O. Sadeh, E. Sobel, A. Shneyour, and Z. Kraiem
Abstract.
Transient neonatal hypothyroidism has been observed in three successive offspring of a mother with autoimmune thyroiditis. Thyroxine replacement therapy was initiated in a 23-year-old woman with overt clinical and laboratory findings of non-goitrous primary hypothyroidism. While on such treatment, she gave birth to three infants manifesting hypothyroidism immediately after birth. The neonates were treated with thyroxine replacement therapy which was discontinued in the three siblings at ages 2½ years, 3½ years, and 13 months. Continuous observation following cessation of therapy revealed clinical and biochemical euthyroidism in the children. Thyroid scanning during the neonatal period in the first child failed to identify functional thyroid tissue, suggesting thyroid agenesis, whereas thyroid scan performed on subsequent follow-up revealed a normal gland. Sequential serum measurements of autoantibodies directed towards the thyrotropin receptor were made in the mother and third child by a cAMP bioassay. High titres (five-six fold above normal) of blocking antibodies (tested by measuring the inhibition of TSH-stimulated cAMP production of cultured human thyroid cells by serum immunoglobulin preparations) were present in the mother and newborn 10 days after birth. The levels remained persistently high in the mother, whereas they declined and were undetectable in the child at four months. Thyroid-stimulating immunoglobulin was absent in both mother and child. The data are compatible with transient neonatal hypothyroidism caused by transplacental transfer of antibodies which block thyroid response to TSH. The half-life of the maternally-derived blocking antibody in the infant was estimated as 1-2 months. This is the first report on sequential serum measurements and estimate of half-life of the blocking antibodies performed by a cAMP bioassay (using thyroid cells of human origin). Unlike the radioreceptor assay employed so far in such cases, this assay can distinguish between stimulating and blocking TSH receptor antibodies.