Home > Newborn Disorders > Congenital hypothyroidism
Congenital hypothyroidism
Overview
Of the causes of congenital hypothyroidism, thyroid agenesis and ectopic thyroid comprise about 75-80% and inborn errors in thyroid hormone synthesis, dysfunction of the hypothalamic-pituitary axis, and thyroid hormone receptor defects comprise the rest. The inborn errors include: thyroid stimulating hormone (TSH) receptor defects, abnormalities of iodide uptake, abnormality in iodide to iodine conversion (peroxidase defect, Pendred syndrome), thyroglobulin defect, and deiodinase defect. Iodine deficiency during pregnancy contributes to congenital hypothyroidism still in many countries. About 10% of those identified by newborn screening will have transient hypothyroidism, often secondary to maternal factors. Though physical findings and symptoms may not be apparent until a few months of life, central nervous system injury may occur during that time.Prevalence
Congenital hypothyroidism occurs in about 1/3,700 live births. The incidence is increased in Hispanic infants, in girls, and in twins, and decreased in boys and in African-Americans. Infants with Down syndrome have a 35-fold increased risk.Inheritance
Most cases are sporadic, but about 15% are inherited as autosomal recessive. Several gene mutations are known to cause congenital hypothyroidism.Other Testing
Newborn screening results may be normal in infants with clinical symptoms. Additional testing is recommended when clinical symptoms are present. False-positive testing may result from samples taken within the first 48 hours of life. Retesting is suggested.Clinical Characteristics
With early treatment, normal growth, development, and IQ can be expected. Without treatment, affected individuals will increasingly develop symptoms as described below, along with growth retardation and irreversible neurodevelopmental impairment.Only about 5% of infants have detectable physical findings or symptoms at birth. Inital signs and symptoms may include:
- hypotonia;
- umbilical hernia;
- puffy face;
- large tongue;
- large fontanelle;
- short fingers and broad hands;
- short legs and arms;
- hyperreflexive jerk with marked slowing of return phase;
- hoarse-sounding voice or cry;
- mottled, cool, dry skin; and
- goiter.
- prolonged jaundice,
- constipation,
- feeding problems,
- distended abdomen, and
- lethargy.
Primary care management
Upon notification of the + screen
- Contact the family and evaluate the infant for poor feeding, lethargy, jaundice;
- Provide urgent treatment/referral if indicated for jaundice, poor feeding, constipation (see the ACT Sheet for elevated TSH (ACMG)
(
349 KB)
for additional information);
- To confirm the diagnosis, work with the following service(s): Utah Newborn Screening Program, (801-584-8256); See also Services below;
- For evaluation and ongoing collaborative management, consult the following service(s): see all Pediatric Endocrinology services providers (6) in our database;
If the diagnosis is confirmed
- Educate the family regarding signs and symptoms;
- Levothyroxine is indicated for affected children and should be monitored and adjusted in collaboration with a pediatric endocrinologist;
- For those identified after irreversible consequences, assist in management, particularly with developmental and educational interventions.
Specialty Care Collaboration
Initial consultation and ongoing collaboration, particularly for medication management. Genetic counseling for the family may be indicated.Resources
Information & Support
For Professionals
ACT Sheet for elevated TSH (ACMG)
( 349 KB)
Developed by the American College of Medical Genetics (ACMG), includes recommended responses to positive newborn screening
test results, diagnostic evaluation, clinical expectations, and sources of additional information. See the ACMG ACT Sheets
and Confirmatory Algorithms (link elsewhere on this page) for more info and sheets on other conditions.
ACT Sheet for Low T4 and/or elevated TSH (ACMG)
( 348 KB)
Developed by the American College of Medical Genetics (ACMG), includes recommended responses to positive newborn screening
test results, diagnostic evaluation, clinical expectations, and sources of additional information. See the ACMG ACT Sheets
and Confirmatory Algorithms (link elsewhere on this page) for more info and sheets on other conditions.
ACT Sheets and Confirmatory Algorithms (ACMG)
The American College of Medical Genetics (ACMG) has developed ACTion (ACT) Sheets and algorithms for responding to positive
newborn screening test results. This page contains a table with links to all of the ACT Sheets and related algorithms.
Congenital hypothyroidism, Utah Newborn Screening Program
( 94 KB)
Article by Rob Lindsay, MD on the Utah Newborn Screening Program's website.
Resource for congenital hypothyroidism (NLM)
Comprehensive compilation of links to information, articles, research, case studies, genetics, and more; from the National
Library of Medicine and the Genetic Alliance.
Congenital hypothyroidism, Contemporary Pediatrics
"Congenital Hypothyroidism: a guide for the general pediatrician" - a review article by Alex Kemper, MD and Carol Foster,
MD from Contemporary Pediatrics, 2003.
Utah Newborn Screening Program
The site provides information and statistics about the program and related legislation, training for practices, and the conditions
screened for.
For Parents and Patients
Congenital hypothyroidism (Genetics Home Reference)
Eeview aimed at patients and families from the National Library of Medicine's Genetics Home Reference site; includes information
on genes involved and inheritance.
Congenital hypothyroidism, parent info (NE Newborn Screening Program)
( 24 KB)
Single page information sheet for parents whose child has a positive screening test.
The MAGIC Foundation
A non-profit organization, providing support services for families of children with a wide variety of chronic and/or critical
disorders, syndromes and diseases that affect growth.
Services
Newborn Screening Programs
Utah Newborn Screening Program,
more info...
44 Mario Capecchi Drive
Salt Lake City, UT 84114
Phone: 801-584-8256
Fax: 801-536-0966
http://health.utah.gov/newbornscreening
For other services related to this condition, browse our Services categories or search our database.
Authors
| Reviewing Author: | Nicola Longo MD, PhD, 3/2007 |
| Compiled and edited by: | Alfred Romeo RN, PhD, 3/2007 |
| Content Last Updated: | 3/2008 |