Harlequin Ichthyosis

Harlequin ichthyosis (HI) and lamellar ichthyosis (LI) are different types of congenital recessive ichthyosis. Harlequin ichthyosis is the most severe form of ichthyosis and life-threatening. Infants are usually born prematurely and are encased in a thick, hard, armor-like covering that severely restricts movements. The taut cast cracks and forms large, diamond-shaped, adherent plates, which are separated by broad, deep, and intense red fissures. The taut skin results in deformation of facial features, such as out-turning of eyelids (ectropium) and lips (eclabium), rudimentary development of nose and ears, and microcephaly. Hands and feet are swollen and covered by a mitten-like casing. Malformations of inner organs are not uncommon. The postnatal period is usually complicated by respiratory distress, dehydration, electrolyte imbalance, temperature instability, feeding problems and bacterial infections, often with fatal consequences. In recent years, an increasing number of patients with prolonged survival have been reported. After shedding the armor-like cast, these survivors developed clinical features of severe non-bullous congenital ichthyosiform erythroderma (CIE) with generalized fine, whitish scale and intense redness. Alopecia, thickening of the skin on palms and soles, and heat intolerance are common. In lamellar ichthyosis, babies are born with a taut, translucent collodion membrane that encases the body and may cause ectropium and eclabium. After the membrane is shed, patients develop white or brown, plate-like scale with no or little redness over the entire body.

Tests Available

Forms and Documents

Test Details

ABCA12
  • A child born with harlequin ichthyosis or with severe congenital ichthyosiform erythroderma
  • An individual of Northern African descent with lamellar ichthyosis without identifiable mutations in TGM1
  • Carrier testing in unaffected family members
  • Recurrence risk calculation
  • Prenatal diagnosis in families with an affected child and known mutation(s)
  • Capillary Sequencing

Ordering

120
3 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL)|Buccal Brushes

Billing

81479x1
No
Yes
  • 757.1 Ichthyosis congenita, Congenital ichthyosis, Harlequin fetus, Ichthyosiform erythroderma
* For price inquiries please email zebras@genedx.com

References

  1. Lefevre et al. Hum Mol Genet 12:2369-78, 2003
  2. Kelsell et al. Am J Hum Genet 76: 794-803, 2005
  3. Akiyama et al. J Invest Dermatol 124: A77, 2005
  4. Thomas AC et al. J Invest Dermatol. 2006 Nov;126(11):2408-13
  5. Thomas et al. Br J Dermatol. 2008 Mar;158(3):611-3
  6. Akiyama Human Mutation 31(10): 1090-1096, 2010

Forms and Documents

Test Details

ABCA12, ABHD5, AGPS, ALDH3A2, ALOX12B, ALOXE3, AP1S1, ARSE, CASP14, CERS3, CLDN1, CYP4F22, EBP, ELOVL4, FLG, GJB2 (Cx26), GJB3 (Cx31), GJB4 (Cx30.3), GJB6 (Cx30), KRT1, KRT10, KRT2, KRT9, LIPN, LOR, NIPAL4(Ichthyin), PEX7, PHGDH, PHYH, PNPLA1, PNPLA2, POMP, PSAT1, SDR9C7, SLC27A4, SNAP29, SPINK5, ST14, STS, TGM1, TGM5, VPS33B, ZMPSTE24
  • Identification of the specific molecular basis of congential ichthyosis or related skin disorders
  • Genetic counseling and recurrence risk assessment
  • Option for prenatal testing in future pregnancies

As needed, based on the referring diagnosis and coverage achieved by the XomeDxSlice-Ichthyosis for a given patient, critical exons with a high yield of mutations will be filled-in by dideoxy sequencing. For any autosomal recessive gene, if one definitive mutation is found by XomeDxSlice sequencing, AND the gene fits the type of ichthyosis reported by the referring physician, capillary sequencing will be used to fill in sequence for exons that are not sufficiently covered (>10X) to find the second mutation. If no second mutation is found by sequencing, deletion/duplication analysis of that gene can be performed at no additional cost can be performed at no additional cost.

Patient samples sent for XomeDxSlice will not be evaluated for secondary findings and therefore will not receive secondary findings as part of their result.\\\"

  • Next-Gen Sequencing

Ordering

708
6 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL)|Dried Blood Spots

Billing

81252x1, 81254x1, 81479x11
Yes
Yes
* For price inquiries please email zebras@genedx.com