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Connections to Hypothyroidism

 

 

Congenital hypothyroidism is a health condition that causes a thyroid hormone production in newborn infants. Congenital hypothyroidism may be cause by an anatomic defect in the thyroid gland, an inborn error of the thyroid metabolism or an iodine deficiency during pregnancy.

 

Signs and Symptoms

  • Decreased activity

  • Poor feeding and weight gain

  • Small stature or poor growth

  • Jaundice

  • Hoarse cry

 

Physical Symptoms and Signs

  • Course facial features

  • Mottled, cool and dry skin

  • Development delays

  • Umbilical hernia

  • Goiter

 

Causes

 

Congenital hypothyroidism may be caused by an anatomic defect in the thyroid gland, an inborn error of thyroid metabolism or an iodine deficiency during mutation. Biologically, congenital hypothyroidism is cause a DNA mutation on the TSHR gene of the genetic sequence.

 

All about the TSHR gene

 

TSHR gene, or the thyroid stimulating hormone receptor gene provides instructions to the thyroid gland to produce thyroid stimulating hormones (TSH). This receptor is produced in the membrane of the thyroid gland. TSH are produced in the thyroid gland with the help of the pituitary gland. These TSHs travel through the bloodstream of the thyroid gland to bind to the TSHR through a series of reactions. This series of reactions control the development and functions of the thyroid gland. From this binding process, the thyroid gland produces thyroid hormones which regulate metabolism, growth and brain development. In congenital hypothyroidism, the TSHR gene is mutated causing a change in one of the chemical building blocks (amino acids) used to make the thyroid stimulating hormone receptor. This is an example missense mutation – a mutation of a codon resulting in a different amino acid placed in the protein sequence. Due to the TSHR gene mutation, the receptor is impaired decreasing the receptor’s ability to bind with thyroid stimulating hormone. This inhibits the production of thyroid hormones overall causing congenital hypothyroidism.

 

 

 

 

 

 

 

 

 

 

 

The mutation is caused during the process of DNA replication.  When the thyroid gland is in need for thyroid hormones, the replication of the TSHR gene occurs. During this progress, an error occurs and is carried out in to the DNA sequence. The DNA of the TSHR gene is carried out through the process of transcription. Transcription produces mRNA of the TSHR gene. The mRNA then goes through the process of translation and produces a polypeptide with mutation. The mutated protein then carries out the production of TSHR. In this case, the bind sites of the TSHR are impaired causing TSH not to bind to the receptor sites. So the thyroid hormone production is not stimulated causing congenital hypothyroidism.

 

Treatment of mutation

 

Congenital mutation must be treat immediately after birth to ensure the full recovery of the thyroid gland. Treatment with daily dose of thyroxine is available through levothyroxine tablets. For infant, a small dose of crush levothyroxine tablet is added to the infant’s milk or water bottle.

 

 

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