Harlequin fetus

Question 1

What is the inheritance pattern of Harlequin fetus?

Answer 1

Autosomal recessive , mutaiton in ABCA 12 gene

Question 2

What prenatal diagnostic methods can be used for Harlequin fetus?

Answer 2

• Amniocentesis—abnormal morphology of amniotic fluid cells
• ultrasound may detect particles in amniotic fluid, “snowflake sign
• Fetal skin biopsy—electron microscopy with absent lamellar bodies

These diagnostic methods help in assessing the condition before birth.

Question 3

What is the incidence of Harlequin fetus?

Answer 3

Less than 1:300,000; M=F

This indicates that the condition is extremely rare and affects both genders equally.

Question 4

At what age does Harlequin fetus typically present?

Answer 4

Birth

Symptoms are usually evident immediately after birth.

Question 5

What are the common pathogenesis factors associated with Harlequin fetus?

Answer 5

• Defective keratinization with abnormal keratinocyte differentiation
• Excessive hyperkeratosis
• Error in lipid metabolism with lipid accumulation in stratum corneum
• Absent normal lamellar granules
• Defective profilaggrin conversion to filaggrin
• Decrease in calpain

These factors contribute to the severe skin abnormalities seen in the condition.

Question 6

What are the key skin features of Harlequin fetus?

Answer 6

• Massive hyperkeratotic plates with deep fissures encasing newborn
• Severe ectropion, eclabium
• Absent/deformed ears, nose, fingers, toes
• Poor temperature regulation
• Generalized scaling with erythroderma in survivors of the neonatal period

These features characterize the appearance and complications faced by affected newborns.

Question 7

What are the differential diagnoses for Harlequin fetus?

Answer 7

• Severe congenital ichthyosiform erythroderma
• Severe lamellar ichthyosis

These conditions share similar skin manifestations and must be differentiated from Harlequin fetus.

Question 8

What investigations should be performed for Harlequin fetus?

Answer 8

Sepsis workup

Due to the high risk of sepsis in affected newborns, a thorough evaluation is necessary.

Question 9

What is the management approach for a newborn with Harlequin fetus?

Answer 9

• Transfer to neonatal intensive care unit
• Monitor fluids, electrolytes, and for sepsis
• Systemic antibiotics
• Humidified incubators
• Retinoids may help shed scale and contribute to survival
• Referral to surgeon for correction of ectropion, hand/feet deformities
• Referral to dermatologist for retinoids, emolliation
• Referral to ophthalmologist to manage ectropion, secondary keratitis

Comprehensive management involves multiple specialists to address the various complications.

Question 10

What is the prognosis for infants with Harlequin fetus?

Answer 10

If not stillborn, most die within the first few days of life as a result of sepsis or respiration and feeding complications; survival has been reported with retinoid therapy

This highlights the critical condition of affected infants and the potential for improved outcomes with treatment.