LAMELLARICHTHYOSIS(LI

Question 1

onsst
gender
AR?
Mutation in what genes

Answer 1

Onset at birth, usually as collodion baby (p. 80).
■ Equally in both sexes; incidence ≤ 1:300,000.
■ Autosomalrecessive.Three types:(1)Mutation o gene encoding transglutaminase 1(TGM1);
(2)Mutationo geneencodinganABClipidtransporter;and(3)Mutationo geneencoding2
lipoxygenases (ALOXIZB, ALOXE3).

Question 2

lesions

Answer 2

■ Soon a ter birth, collodion membrane shed with subsequent large, coarse, tessellated scales involv-
i n g t h e e n t i r e b o d y ( F i g s . 4 - 7 a n d 4 - 8 ) . Th e s c a l e s a r e t h i c k , b r o w n , a c c u m u l a t e d o n l o w e r e x t r e m i -
ties, exural areas involved (Fig. 4-9).
■ Hands, eet involvement varies;accentuation o palmar/plantar creases.
■ Eyes:Extropium(Fig.4-7)andeclabium.
■ Scalp: Hairs bound down by scales; scarring alopecia.
■ Mucous membranes; nails: Occasional dystrophy secondary to nail old in ammation.
■ Heat intolerance; obstruction o eccrine glands impairs sweating

Question 3

lab

mgt

Answer 3

Laboratory: Acanthosis; hyperkeratosis, granular layer present. Epidermal transglutaminase ↓ in
transglutaminase-de cient subtype.
■ Course: Persists throughout li e, no improvement with age.
■ Management: Newborn, see collodion baby, p. 80. Adults: Emollients, keratolytics, systemic retinoids
as in DIVand XLI. Instruct about overheating.