Harlequin ichthyosis is a very rare autosomal recessive disease. And the mutation of the ABCA12 gene is mostly responsible for this incurable problem. It comes under a severe genetic disorder that mainly affects the skin of the newborn.
This condition is very uncommon, seen in around 1 in 300,000 births. Here the newborn is having abnormal dry, thick, and deep crack skin which are split apart. The first case of harlequin ichthyosis is documented in a diary entry by Reverend Oliver in America in 1750.
The infants born with harlequin ichthyosis are having a massive disruption of the barrier(skin). The scaly and trapezoid-shaped skin plates make the baby immunocompromised. Also causes hyperkeratosis. The baby’s body is unable to control water loss, maintain the temperature, and fail to fight infections.
Why is harlequin ichthyosis considered as rare?
Till now, harlequin ichthyosis or harlequin fetus (synonym) is considered as limited and exact incidence is undiscovered. And according to a 2014 paper. It was written by Ahmed H and O’ Toole EA, two researchers from the department of dermatology, Barts Health National Health Service Trust, one in 300,000 babies suffering from this.
How is it inherited?
As it is an autosomal recessive disorder, inherited from both parents. Both parents should be the carrier of the mutated ABCA12 gene. The baby’s parents don’t show any signs of harlequin ichthyosis. But, they have the one copy of the mutated gene for which their baby has to suffer.
If the baby is a carrier then he must have received one normal gene and one mutated gene. The risk for having an affected child is, both parents are the carriers.
What are the signs and symptoms?
The symptoms are like;
- Restricted movement of the chest can lead to breathing difficulties
- Limited movement of the arms and legs
- Abnormal changes in temperature
- Cracked skin
- Fish mouth
- Ears and nose are poorly developed
- Cranial and facial deformity
- Bleeding during birth
- Lips pull back by the dry skin, eclabium
About 80-99% of infants having ichthyosis fetalis show the above symptoms.
Symptoms in adults
The ichthyosis symptoms shown in adults are,
- Poor physical development
- Hearing problems due to scaly skin in ears
- Thin hairs
- Redfish scale skin
- Hypoplasia found in fingers
What is the cause behind HI (harlequin ichthyosis)?
Mutated genes are the only cause behind this. The ABCA12 is the victim gene that failed to do its function. It does not give proper instruction to make protein.
Proteins like keratin are very much necessary for the skin to develop naturally. So, the ABCA12 gene makes it. And transports fat to the epidermis. Lastly, create an effective skin barrier in the newborn.
Due to the mutated gene, the fat can’t reach the epidermis and form skin.
What are the diagnostic evaluations?
Harlequin ichthyosis is diagnosed by prenatal screening. It may be amniocentesis or chorionic villus sampling. In both cases, take the sample of fetus DNA. It gives full confirmation about the mutated ABCA12 gene.
The genetic testing registry (GTR) gives full information about genetic screening. In this GTR, the health care providers and researchers are the intended audiences.so, genetic testing is a confirmatory test for it.
Also, do the diagnosis by the newborn’s appearance and physical assessment which measures at birth. Also, do a Lab test with histopathological examination like a biopsy. At last, the findings from the biopsy result are hyperkeratosis.
Treatment for harlequin ichthyosis
- Constant supportive care is always necessary for this genetic disorder.
- Moisturizing creams, antibiotic therapy, retinoids can increase the chances of survival in newborns.
- Give nasogastric tube feeding to avoid dehydration and malnutrition.
- Lubricate the eyes of the newborn with special lubricating cream.
- Insert a tube to maintain the patency of the airway.
- Cover the overall skin of the baby to prevent infections.
How to manage it?
- The management of harlequin ichthyosis is very simple as well as very effective. In this, we can do certain things to protect the baby’s skin from infections. It also helps to regulate the body temperature and prevent dehydration.
- Along with use the products that are loading with moisturizing effects like, alpha- hydroxy acids, ceramides, cholesterol, ointment, etc. for better results, use ointment and moisturizer just after a bath.
- Also, use oral retinoids to avoid sunburn and skin irritation. If the child is in school then consult with the school day nurse to look after your child.