congenial hypothyroidism

2. Congenital Hypothyroidism
Dr. Sunil Natha Mhaske

3. • Hypothyroidism is a condition in which the thyroid gland, does not produce enough thyroid
hormones, which control overall metabolism and many bodily functions.
• Hashimoto’s disease-body’s immune system mistakenly destructs its own thyroid gland.
• Congenital hypothyroidism is when the disorder is present in a baby at birth.
• A condition of thyroid hormone deficiency present at birth marked by arrested physical and
mental development, dystrophy of the bones and soft parts and lowered basal
metabolism.
• Congenital form of thyroid deficiency
• Myxedema is the acquired form.
• 1 in 4000 newborn.
Introduction-

4. Risk factors for congenital hypothyroidism –
 A chromosomal disorder such as Down syndrome, Williams
syndrome, or Turner syndrome.
 An autoimmune disorder such as type 1 diabetes or celiac disease.
 Injury to the thyroid gland.
Congenital hypothyroidism with associated syndromes-
- Pendred syndrome
- Bamforth-Lazarus syndrome
- brain-lung-thyroid syndrome.

5. OMIM Name Gene
275200 Congenital hypothyroidism,
nongoitrous 1 CHNG1
TSHR
218700 CHNG2 PAX8
609893 CHNG3 ? at 15q25.3-q26.1
275100 CHNG4 TSHB
225250 CHNG5 NKX2-5
When inherited, the condition usually has an autosomal recessive inheritance pattern,
which means both copies of the gene in each cell have mutations. Typically, the parents of an
individual with an autosomal recessive condition each carry one copy of the mutated gene,
but they do not show signs and symptoms of the condition.
Genetic types

6. The most common cause of congenital hypothyroidism is failure of the thyroid gland to grow
before birth.
• Iodine deficiency.
• Defect of development of the thyroid gland.
• Genetic defects
• Presence of maternal antibodies.
• Maternal intake of drugs- Radioiodine, iodides, propylthiouracil, methimazole.
• Idiopathic
Etiology-

7. 1) Neonatal period-
• Pallor and hypothermia
• Enlarged tongue
• Hypotonia
• Prolonged jaundice
• Rough, dry skin
• Open posterior fontanelle
• Relative constipation
• Mild post-maturity
• Heavy baby
2) After 1 month-
• Umbilical hernia
• Pallor & hypothermia
• Large tongue
• Rough, dry skin
• Constipation
• Facial puffiness
• Growth retardation
• Poor development
• Myxedema
• Umbilical hernia
Clinical features:

8. Skeletal features:

10. Diagnosis-
• Estimation of T3, T4 and TSH (on day 5 to 7 of postnatal life)- TSH > 20 miu/I.
Radiological changes-
• Widely open anterior and posterior frontally.
• Depressed nasal bridge
• Retardation of osseous development
• Absent distal femoral epiphysis at birth
• Large skull with wide sutures
• Cortical thickening

11. • X ray skull sellar view showing enlarged sella hypoplastic maxillary and frontal sinuses

12. X ray wrist showing bone age of 10
years (chronological age 24 years):
1. Epiphysis of pisiform just appearing
2. Irregular ossification of growth plate
3. Sclerotic band at radial metaphysis
4. Soft tissue thickening
5. Pencil thin cortex

13. X ray spine showing-
1. Bullet shaped L1 vertebra
2. Osteoporosis
3. Increased inter vertebral spaces

14. Xray pelvis showing-
1. Unfused femoral head epiphysis
2. Unfused apophysis
3. Pencil thin cortex
4. Persistent tri radiate cartilage

15. X ray knee showing heterogeneous epiphysis with
irregular ossification of growth plate

16. Differential diagnosis-
• Goiter
• Down syndrome
• Skeletal dysplasia
• Biliary atresia
• Hypopituitariosm
• Iodine syndrome
• Pituitary dwarfism
• Panhypopituitarism
• Metabolic storagae disease

17. Complications-
• Mental retardation
• Impairment of linear growth
• Impairment of bone maturation
• Gait abnormalities
• Spasticity
• Dysarthria
• Mutism
• Autistic behavior

18. Treatment-
• Synthetic form of the thyroid hormone T4- levothyroxine
• Dose : child-4 microgram/kg/day, Adult-2 microgram/kg/day – orally
• Side effects : craniosynostosis, pseudotumor cerebri
• Don't mix the levothyroxine with soy formula or calcium or iron preparations - reduces
the absorption.

19. Prognosis-
• Most children born with congenital hypothyroidism and correctly treated with thyroxine
grow and develop normally in all respects.
• Even most of those with athyreosis and undetectable T4 levels at birth develop with
normal intelligence, although as a population academic performance tends to be below
that of siblings and mild learning problems occur in some.
• Congenital hypothyroidism is the most common preventable cause of intellectual
disability.

20. Evaluation-
Serum T4 or free T4 and TSH blood tests should be performed-
• At 2 and 4 weeks after the initiation of T4 treatment.
• Every 1 to 2 months during the first 6 months of life.
• Every 3 to 4 months between 6 months and 3 years of age.
• Every 6 to 12 months thereafter until growth is complete.
Newborn thyroid screening-
• Blood sample is taken by a heel prick of the baby.
• For early diagnosis and proper treatment of thyroid disorders in children
• It is one of the treatable and preventable cause of mental retardation

21. National Iodine Deficiency Disorder Control Programme –
• Implemented since 1962.
• Objective of reducing and preventing iodine disorder control programme.
• To assess the magnitude of the iodine deficiency disorders.
• Supply of iodized salt in place of common salt.
• Laboratory monitoring of iodized salt and urinary iodine excretion.
• Health education & publicity.
• Goal: to decrease prevalence of goiter to <5% in the school children age 6-12 years.

22. Thank you.