Autosomal Recessive Congenital Ichthyosis, TGM1 Related

Gene : TGM1

What is Autosomal Recessive Congenital Ichthyosis?

Autosomal Recessive Congenital Ichthyosis, also known as ARCI, is a group of inherited disorders that mainly affects the skin, causing abnormal skin scaling all over the body. The clinical presentation and severity of ARCI may vary significantly. Infants with harlequin ichthyosis, the most severe and often fatal type, are usually born prematurely and are covered in thick, hard, armor-like plates of skin. This covering severely restricts movement and can cause deformities of the body. Life-threatening complications in the immediate postnatal period for babies with harlequin ichthyosis include breathing difficulties, feeding problems, and infection. Babies with the more common and somewhat less severe types, lamellar ichthyosis (LI) and nonbullous congenital ichthyosiform erythroderma (CIE) are born with a tight, clear sheath covering their skin called a collodion membrane. These newborns are often referred to as collodion babies. This membrane is usually shed during the first few weeks of life, but remaining effects include scaly skin and outward turning eyelids and lips. People with LI typically have large, dark, plate-like scales covering their skin, while people with CIE have finer, whiter scales and underlying generalized redness of the skin. Additional symptoms may include hair loss, a decreased ability to sweat, joint deformities, and a thickening of the skin on the palms of the hands and soles of the feet. There is no cure for ARCI; however, with careful medical care and surveillance, life expectancy is not expected to be affected. One of the causes of ARCI is pathogenic variants in the TGM1 gene.

How is autosomal recessive congenital ichthyosis inherited?

ARCI is inherited in an autosomal recessive manner. This type of inheritance requires the presence of two copies of a pathogenic variant in the gene for a person to have the genetic disease. Both parents must be carriers of a pathogenic variant in the gene in order to be at risk to have an affected child. The child must inherit a pathogenic variant from each carrier parent in order to be affected. There is a 1 in 4 chance that a baby will inherit two mutated copies of the gene and be affected when both parents are carriers.

What does it mean to be a carrier?

There are generally no signs or symptoms associated with being a carrier ARCI. However, the risk to have a child affected with ARCI is increased. Testing of reproductive partners is recommended for carriers of ARCI.

How common is autosomal recessive congenital ichthyosis?

ARCI affects approximately 1 in 200,000 newborns in the US, but it is seen in higher frequency in certain populations. The frequency of lamellar ichthyosis is estimated at 1 in 91,000 newborns in Norway, and 1 in 122,000 newborns in Galicia (northern Spain).

Family References and Resources
Clinician References
What is Analyzed?
  • Full gene sequencing
Affected Systems



Carrier Rates
Detection Rate
Carrier Frequency
General Population > 99% 1 in 300

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