RESUMO
OBJECTIVE: To determine the diagnostic and predictive value of ultrasound and radioisotope scans of the thyroid, alone and in combination, during a single visit after initial referral by the screening laboratory with thyroid-stimulating hormone (TSH) elevation. STUDY DESIGN: Retrospective blind review of ultrasound and radioisotope images followed by final diagnosis based on clinical features, biochemistry, imaging, and molecular genetic study. RESULTS: Infants (n = 97; 61 female) with median birthweight 3.38 kg (range 2.04-4.86) and gestation 40 weeks (range 33-42), underwent successful dual thyroid ultrasound and technetium-99m pertechnetate radioisotope scan in a single center. Combined scanning at the initial visit resulted in a correct final diagnosis in 79 of 97 (81%) cases. One patient was misdiagnosed initially as having athyreosis as the result of delayed radioisotope scan and the diagnosis of ectopia made later on diagnostic challenge. The specificity/sensitivity for radioisotope scan and for ultrasound was as follows: 100%/97% and 100%/55% for ectopia (n = 39); 81%/100% and 54%/100% for athyreosis (n = 18); and 89%/90% and 80%/95% for dyshormonogenesis (n = 20). Neither modality, alone or in combination, predicted final diagnosis in eutopic glands due to hypoplasia (n = 4), transient TSH elevation (n = 12), and status still uncertain (n = 4). CONCLUSION: More than 80% of newborn infants with TSH elevation can be diagnosed correctly on initial imaging with combined radioisotope scan and ultrasound. Ultrasound cannot reliably detect thyroid ectopia. Radioisotope scan, especially if performed late, may show no uptake despite the presence of a eutopic gland.
Assuntos
Hipotireoidismo/diagnóstico por imagem , Imagem Multimodal , Triagem Neonatal/métodos , Compostos Radiofarmacêuticos , Pertecnetato Tc 99m de Sódio , Tireotropina/sangue , Feminino , Humanos , Hipotireoidismo/sangue , Recém-Nascido , Masculino , Valor Preditivo dos Testes , Cintilografia , Encaminhamento e Consulta , Estudos Retrospectivos , UltrassonografiaRESUMO
Hypothyroidism was documented by cordocentesis at 19 weeks in a fetus with non-immune goiter. Intra-amniotic thyroxine was injected at 25 weeks when amniotic fluid volume increased. Psychomotor outcome was normal. We argue that intra-amniotic thyroxine should not be used to treat the hypothyroidism but only to correct the development of polyhydramnios.
Assuntos
Hipotireoidismo Congênito/terapia , Doenças Fetais/terapia , Bócio/congênito , Tiroxina/administração & dosagem , Adulto , Líquido Amniótico , Hipotireoidismo Congênito/diagnóstico por imagem , Cordocentese , Feminino , Doenças Fetais/diagnóstico por imagem , Bócio/diagnóstico por imagem , Humanos , Masculino , Poli-Hidrâmnios/prevenção & controle , Gravidez , Segundo Trimestre da Gravidez , Tireotropina/sangue , Ultrassonografia Pré-NatalRESUMO
PURPOSE: To determine the role of cytochrome P450IBI (CYP1B1) mutations in causing primary congenital glaucoma (PCG) in a cohort of Native Americans from Quito, Ecuador. MATERIALS AND METHODS: Seventeen patients with PCG from 15 Native American families were recruited from the Ophthalmology Clinic at Hospital Metropolitano, Quito, Ecuador. Experienced ophthalmologists examined all affected study subjects. Purified DNA was prepared from peripheral blood samples and CYP1B1 coding exons (exons 2 and 3) were amplified and sequenced. Southern blot was performed only on those affected patients who showed no mutations in the CYP1B1 coding exons. RESULTS: The molecular basis of PCG in two families was determined: two novel mutations (a deletion and a point mutation) and one novel polymorphism in CYP1B1 were identified in addition to a previously described single amino acid substitution. Southern blot analyses on whole genomic DNA from affected individuals in whom no mutations were identified by the direct PCR/sequencing approach did not detect any large rearrangements or mutations outside the coding region. CONCLUSION: These findings suggest that mutations in CYPIBI are not a major cause of PCG in this population and that at least one additional locus for this condition is responsible for most cases. Further, the PCG phenotype did not correlate readily with the molecular basis of the disorder, suggesting that careful clinical analysis of the phenotype cannot predict the molecular basis of the disease with accuracy.