SNP Shot: Genomic Insights

Netherton syndrome is a genetic condition impacting the skin, hair, and immune system. Infants born with it often present with red, scaly skin (ichthyosiform erythroderma) that may weep fluid. A tight, clear membrane (collodion membrane) may cover the skin at birth, typically shedding within weeks. Due to the compromised skin barrier, newborns are susceptible to dehydration and potentially life-threatening infections (sepsis). These infants may also experience growth delays (failure to thrive). While the health of older children and adults generally improves, they often remain underweight and short.

After infancy, the severity of skin symptoms varies and can change over time. The skin might remain red and scaly, particularly during early childhood. Some individuals experience intermittent redness or outbreaks of ichthyosis linearis circumflexa, characterized by ring-shaped skin lesions. The triggers for these outbreaks are unknown, but stress or infections are suspected contributing factors.

Persistent itching is a common concern, and scratching increases the risk of skin infections. The rapid shedding of dead skin cells can lead to buildup in the ear canals, potentially affecting hearing if not regularly cleared. The skin's increased absorbency can cause elevated blood levels from topical medications. Impaired temperature regulation can also occur due to the skin's reduced protective function against heat and cold.

Individuals with Netherton syndrome often have fragile hair that breaks easily. Some hair strands exhibit variations in thickness, known as bamboo hair (trichorrhexis nodosa or trichorrhexis invaginata). This abnormality can affect scalp hair, eyelashes, and eyebrows. It might not be immediately apparent in infants with sparse hair.

Many individuals with Netherton syndrome experience immune system issues such as food allergies, allergic rhinitis (hay fever), asthma, or eczema (an inflammatory skin condition).

Inheritance:

Netherton syndrome follows an autosomal recessive inheritance pattern. This means an affected individual inherits a mutated copy of the responsible gene from each parent. While both parents carry one copy of the mutated gene, they usually do not exhibit any symptoms of the condition themselves.