Autosomal Recessive Congenital Ichthyosis

Autosomal recessive congenital ichthyoses (ARCI) form a heterogeneous group of disorders characterized by generalized scaling and variable degree of redness of the skin. ARCI manifests at birth or infancy, generally without primary involvement of other organ systems (non-syndromic). The skin features of ARCI may overlap considerably with various types of syndromic ichthyoses (see our website www.genedx.com for information on other types of ichthyoses). The 3 major types of non-syndromic ichthyoses include Harlequin ichthyosis (HI), lamellar ichthyosis (LI) and congenital ichthyosiform erythroderma (CIE). Most neonates with ARCI present as collodion babies with a taut, translucent or opaque membrane that encases the entire body and lasts for days to two weeks. In severe cases, ectropion, eclabium, and scarring alopecia of the scalp and eyebrows may be present. After shedding the collodion membrane, the presentation and severity of ARCI between individuals can vary significantly. At one end of the spectrum is severe ‘classic’ lamellar ichthyosis (LI), which is characterized by large, dark brown, plate-like scale without underlying erythroderma. At the other end is severe ‘classic’ CIE, with fine, whitish scale and intense redness (erythroderma) of the skin. The clinical features of CIE can be milder than in LI and demonstrate a greater variability in the intensity of redness, scale, and involvement of palms and soles. However, CIE may cause substantial metabolic stress in young children and growth delay. There are also cases of (almost) complete resolution of the skin disorder, so-called ‘self-healing collodion ichthyosis’. Distinguishing between these disorders on clinical grounds can be useful for clarifying prognosis and management and, to some extent, to choose which genes to analyze. A skin biopsy is not necessary to establish the diagnosis of ARCI, and is usually not helpful in differentiating among the different clinical disorders along the spectrum. However, a skin biopsy is useful to differentiate ARCI from the bullous forms of ichthyosis (epidermolytic ichthyosis, also known as epidermolytic hyperkeratosis).

Tests Available

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|Buccal Swabs

Billing

81252x1, 81254x1, 81401x1, 81479x1
Yes
Yes
* For price inquiries please email zebras@genedx.com