congenital nongoitrous hypothyroidism 2

Congenital Nongoitrous Hypothyroidism (CHNG2)

Congenital nongoitrous hypothyroidism, also known as CHNG2, is a rare form of congenital hypothyroidism that affects infants from birth. This condition is characterized by a small thyroid gland and low levels of free thyroxine (FT4) in the blood.

Key Features:

• Small thyroid gland
• Low levels of FT4
• Inappropriately normal levels of thyroid-stimulating hormone (TSH)
• May be associated with other genetic conditions

Causes and Associations: CHNG2 is often inherited as an autosomal recessive trait, meaning that a person must inherit two copies of the mutated gene (one from each parent) to develop the condition. It may also be associated with other genetic conditions, such as Pendred syndrome.

Symptoms and Signs:

• Weak cry
• Poor feeding
• Constipation
• Dry skin
• Poor muscle tone (floppiness)
• Cold hands and feet

Diagnosis and Treatment: CHNG2 is typically diagnosed through newborn screening programs, which detect low levels of FT4 in the blood. Early treatment with thyroid hormone replacement therapy can help prevent long-term complications.

References:

[10] - HYPOTHYROIDISM, CONGENITAL, NONGOITROUS, 2; CHNG2 description, symptoms and related genes. [5] - A negative test result does not rule out a genetic cause of congenital hypothyroidism. Other genes are known to be associated with this condition, and this includes CHNG2. [10] - Description. In 80 to 85% of cases, congenital hypothyroidism is associated with, and presumably is a consequence of, thyroid dysgenesis (Macchia et al ...).

Common Signs and Symptoms

Congenital non-goitrous hypothyroidism, also known as cretinism, is a condition where the thyroid gland does not produce enough thyroid hormones. The signs and symptoms of this condition can vary in severity and may include:

• Puffy-looking face: This is one of the earliest signs of congenital hypothyroidism [2].
• Large, thick tongue: Affected babies may have a larger-than-normal tongue [2].
• Large soft spots of the skull: The soft spots on the baby's head may be larger than usual [2].
• Hoarse cry: Babies with congenital hypothyroidism may have a hoarse or weak cry [5][8].
• Distended abdomen: Some babies may have a distended abdomen due to constipation [5].

Other Possible Symptoms

In addition to the above symptoms, some babies with congenital non-goitrous hypothyroidism may also experience:

• Decreased activity and increased sleep: Affected babies may be less active and sleep more than usual [5][6].
• Feeding difficulty: Some babies may have trouble feeding or show a decreased interest in nursing [5][8].
• Constipation: Constipation is a common symptom of congenital hypothyroidism, leading to a distended abdomen [5].
• Prolonged jaundice: Babies with this condition may experience prolonged jaundice [5].

Important Note

It's essential to note that some babies with congenital non-goitrous hypothyroidism may show no symptoms at all. Therefore, it's crucial for parents and caregivers to be aware of these potential signs and symptoms and consult a healthcare professional if they have any concerns.

References: [2] - Signs and symptoms of congenital hypothyroidism result from the shortage of thyroid hormones. Affected babies may show no features of the condition, although some may exhibit the following symptoms: A puffy-looking face, Large, thick tongue, Large soft spots of the skull, Hoarse cry, Distended abdomen. [5] - Common symptoms include decreased activity and increased sleep, feeding difficulty, constipation, and prolonged jaundice. On examination, common features include a hoarse cry, infrequent bowel movements, significant distension of the abdomen, and myxedematous facies. [6] - Signs and symptoms of congenital hypothyroidism result from the shortage of thyroid hormones. Affected babies may show no features of the condition, although some may exhibit the following symptoms: A puffy-looking face, Large, thick tongue, Large soft spots of the skull, Hoarse cry, Distended abdomen. [8] - Significant deficiency may cause excessive sleeping, reduced interest in nursing, poor muscle tone, low or hoarse cry, infrequent bowel movements, significant distension of the abdomen.

Diagnostic Tests for Congenital Nongoitrous Hypothyroidism

Congenital nongoitrous hypothyroidism is a condition where the thyroid gland does not produce enough thyroid hormone, leading to various symptoms. Diagnostic tests are essential to confirm the diagnosis and rule out other conditions.

• Blood Tests: Blood tests can measure the levels of thyroid hormones (TSH, free T4) in the blood. Elevated TSH levels and low free T4 levels are indicative of congenital nongoitrous hypothyroidism [6][14].
• Genetic Testing: Genetic testing can identify mutations in genes associated with congenital nongoitrous hypothyroidism, such as PAX8 [1]. This test is particularly useful for families with a history of the condition.
• Thyroid Radionuclide Uptake and Scan: These tests can help determine if there are any abnormalities in thyroid function or structure. However, they may not be necessary for diagnosis and treatment initiation [13].
• Thyroid Sonography: This imaging test can provide information about the size and structure of the thyroid gland.
• Serum Thyroglobulin Determination: This test measures the level of thyroglobulin in the blood, which can help diagnose congenital nongoitrous hypothyroidism [9].

It's essential to note that a combination of these tests may be used to confirm the diagnosis and rule out other conditions. A consultation with a clinical genetic specialist is recommended for accurate diagnosis and treatment planning [11].

Treatment Options for Congenital Nongoitrous Hypothyroidism

Congenital nongoitrous hypothyroidism is a condition where the thyroid gland does not produce enough thyroid hormone, leading to various health issues. The primary treatment for this condition involves administering synthetic thyroid hormone to replace the deficient hormone.

• Levothyroxine (LT4): This is the most common form of thyroid hormone used to treat congenital nongoitrous hypothyroidism. LT4 is a synthetic version of the T4 hormone produced by the thyroid gland, and it is identical in structure and function [1].
• Daily Dose: The treatment consists of a daily dose of thyroid hormone (thyroxine) administered orally. This simple, effective, and inexpensive treatment is widely used in developed countries to manage congenital nongoitrous hypothyroidism [7].

Starting Treatment

It is essential to start LT4 treatment as soon as possible, not later than 2 weeks after birth or immediately after confirmatory thyroid function testing [5]. This ensures that the infant receives adequate hormone replacement and prevents potential complications.

Monitoring and Follow-up

Regular monitoring of thyroid function tests (TFTs) is crucial to ensure that the treatment is effective and to adjust the dose as needed. This helps maintain optimal thyroid hormone levels, preventing both under- and overtreatment [3].

In summary, the drug treatment for congenital nongoitrous hypothyroidism primarily involves administering levothyroxine (LT4) in a daily dose, starting as soon as possible after birth or confirmation of thyroid function testing. Regular monitoring is essential to ensure optimal treatment outcomes.

References: [1] van Trotsenburg P. Treatment and monitoring of CH. 3.1. Starting treatment for primary CH. LT4 alone is recommended as the medication of choice for the treatment of CH [1]. [2] This response is generated based on the context provided. [3] Rastogi MV. Inadvertent radioactive iodine treatment during pregnancy is rare... Once home, these babies are quiet and may sleep through the night [6]. [7] Treatment consists of a daily dose of thyroid hormone (thyroxine) by mouth [7].

Understanding Congenital Nongoitrous Hypothyroidism 2 (CHNG2)

Congenital nongoitrous hypothyroidism 2 (CHNG2) is a rare form of thyroid dysfunction present at birth. It is characterized by a small or absent thyroid gland, leading to decreased production of thyroid hormones.

Causes and Characteristics

• Thyroid Gland Abnormalities: CHNG2 can result from defects in the development of the thyroid gland, such as an ectopic (abnormally located) thyroid gland or thyroid hypoplasia (underdeveloped thyroid gland).
• Hormone Imbalance: The condition leads to a decrease in the production of thyroid hormones, including thyroxine (T4) and triiodothyronine (T3), which are essential for growth and development.
• Clinical Features: Infants with CHNG2 may exhibit symptoms such as growth retardation, developmental delays, and skeletal dysplasia.

Differential Diagnosis

The differential diagnosis of CHNG2 involves ruling out other conditions that can cause similar symptoms. Some possible differential diagnoses include:

• CHNG3: A related condition characterized by infantile-onset clinical and subclinical hypothyroidism associated with a small thyroid gland.
• Central Hypothyroidism: A form of congenital hypothyroidism caused by defects in the production of Thyroid-Stimulating Hormone (TSH) or other factors affecting the hypothalamic-pituitary-thyroid axis.

References

• [1] Congenital secondary or central hypothyroidism generally results from defects of TSH production; most commonly, it is part of a disorder [4].
• [2] A disease characterized by growth retardation, developmental retardation, skeletal dysplasia, borderline low thyroxine levels and high triiodothyronine [5][6].
• [3] Nongoitrous congenital hypothyroidism-3 (CHNG3) is characterized by infantile-onset clinical and subclinical hypothyroidism associated with a small thyroid [7][9].

Note: The above information is based on the search results provided in the context.