Congenital disorders
Everything You Should Know About the Rare Disorder Aplasia Cutis Congenita
Aug
Aplasia cutis congenita (ACC) is a rare genetic disease that causes missing skin in newborns. In some cases of aplasia cutis congenita, underlying structures beneath the skin are also absent. This can lead to internal organs being visible outside the body. Though it mainly affects a newborn’s scalp, it can develop anywhere on the body.
This article discusses everything parents should know about aplasia cutis congenita.
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What Causes Aplasia Cutis Congenita?
Aplasia cutis congenita is a genetic disease. That means one or more fetal genes do not function as they should during fetal development because of genetic variations. There are several genes associated with the development of aplasia cutis congenita, including:
- PLEC: Provides instructions to create plectin, a protein used in tissues such as the skin and muscles.
- ITGB4: Provides instructions to help create integrin, a protein that regulates cell attachment and adhesion.
- BMS1: Regulates the encoding of other genes.
- DLL4: Provides instructions to create a protein required for the Notch pathway, a signaling pathway in charge of cell proliferation, differentiation, and death.
When these genes do not operate as they should, they can cause aplasia cutis congenita to develop in newborns.
Though the exact cause of aplasia cutis congenita is unknown, several factors are currently considered possible causes, including:
- Intrauterine trauma and infections
- Insufficient placenta due to tissue death
- Drug use during pregnancy
- Genetics
Understanding Gene Variations
A genetic variant occurs when a gene’s coding is atypical for most people. There are two types of these variants: benign and pathogenic. Benign variants do not cause disease, whereas pathogenic variants can.
Signs and Symptoms
The main symptom associated with ACC is a lack of skin and hair in localized areas present at birth. Up to 70% of ACC cases affect the scalp, but ACC can also be seen on the:
- Trunk/torso
- Arms
- Legs
In some more severe cases, the bone beneath the skin may also be missing, leaving only a thin, transparent membrane that makes internal organs visible outside the body. Typically, the lack of skin replaced by the transparent membrane is the only sign of disease.
However, other signs and symptoms can occur, such as:
- Palsy on one side of the face (paralysis)
- Macrocephaly, or having an unusually large head
- Congenital heart anomalies, issues with the structure of the heart at birth
- Toe or finger webbing
- Increased bleeding time when injured
- Abnormal bone mineral density
- Skin ulcers
- Spinal dysraphism, which is an umbrella term for describing spinal disorders that develop in the womb
- Lesions on the skull or skull defects
Reproduced with permission from © DermNet dermnetnz.org 2023.
Diagnosing Aplasia Cutis Congenita
During the first few days of an infant’s life, ACC is monitored by healthcare providers for its symptoms, which often serve as the primary diagnostic tool. The condition is most often discovered at birth, but in some cases, prenatal ultrasounds can identify it based on the appearance and scope of the disease while the fetus is still growing in the womb.
Imaging tests, such as magnetic imaging resonance (MRI), may assess the condition of the central nervous system and check for variants of ACC and other disorders associated with it.
Other possible tests include:
How Common Is ACC?
ACC is incredibly rare. Research has found a low incidence rate, and in 2019, only 500 known cases of ACC existed globally.
Is Aplasia Cutis Congenita Life-Threatening?
According to research, aplasia cutis congenita isn’t typically life-threatening in and of itself. That said, complications that can arise due to the disorder can lead to death.
This is because the area where the skin is gone, known as lesions, can act as open wounds and lead to life-threatening complications, including:
In most cases, these lesions heal over time, and newborns recover from the disorder.
What Is the Survival Rate of ACC?
ACC can be life-threatening, but that’s not always the case. In fact, the disorder has a high survival rate of roughly 78%.
Aplasia Cutis Congenita Treatment
Treating ACC rarely requires invasive options. The steps to treating ACC include:
- Treating the lesion/wound using disinfecting solutions and ointments
- Covering the wound with ionic silver dressing and sterile gauze
- Replacing the wound dressing every two to three days to prevent infection
Intravenous antibiotics can also treat ACC to ensure that an infection doesn’t occur because of the condition’s lesions. Nutritional IVs will also ensure newborn infants get all the nutrition they need while their lesions heal.
In severe cases when a large area of the body is affected, a skin graft may treat the condition. A skin graft replaces healthy skin on top of the affected areas. This surgical intervention is often a last resort.
Summary
Aplasia cutis congenita is an incredibly rare disorder that affects fetuses and newborns. When a person is born with aplasia cutis congenita, certain body areas are missing skin and/or bone. In some cases, the area with missing skin is marked by a lesion with the risk of infection or bleeding.
Treatment is often conservative and focuses on healing the lesion and affected area while preventing complications, such as an infection. In severe cases, skin graft surgery may restore healthy skin to a large body area. The outlook for ACC is good, and close to 80% of people born with the disorder go on to lead healthy lives.
