X-LINKEDRECESSIVEICHTHYOSIS(XLRI)

Question 1

gender.

genes locus

Answer 1

males, x-linked recessive; gene locus Xp22.32.

Question 2

defiecient in what

Answer 2

Steroid sul atase de ciency.

Question 3

lesions

absence of involvement where

Answer 3

■ Onset soon a ter birth.
■ Prominent, dirty brown scales on the neck, extremities, trunk, and buttocks (Fig. 4-5).
■ Involvement o exural regions (Fig. 4-6).
■ Absence o palm or sole involvement.
■ Comma-shaped stromal corneal opacities (asymptomatic) in 50% o adult males. Present in some
emale carriers.

Question 4

tx

Answer 4

Management: Hydration o stratum corneum and keratolytic agents as in ichthyosis vulgaris. Marked
improvement with systemic retinoids (acitretin and isotretinoin), intermittent treatment with care ul monitoring o toxicity.

Question 5

laboratory

Answer 5

Laboratory:Cholesterolsulatelevel↑;increasedmobilityo β-lipoproteinsinelectrophoresis.Steroid
sul atase decreased or absent. Dermatopathology: Hyperkeratosis and granular layer present