ichthyosis vulgaris mutation/inheritance
filaggrin mutation–defective/abnormal synthesis of filaggrin, AD inheritance
ichthyosis vulgaris clinical
starts few months after birth, large adherent scales on extensor surfaces of extremities (fish scales). smaller scales on other surfaces. Spares flexural creases. +KP, HK on palms/soles
ichthyosis vulgaris acquired variant
ichthyosis vulgaris path
ichthyosis vulgaris EM
X-linked ichthyosis inheritance/genetics
- absence of steroid sulfatase activity
X-linked ichthyosis clinical
rarely present at birth. female carriers are frequently affected, but men have more severe.
-scale thickness increases in childhood
+involvement of flexural creases
X-linked ichthyosis path
steroid sulfatase role in x-linked icthyosis
epidermolytic hyperkeratosis (EHK) inheritance
-AD
EHK synonym
bullous congenital ichthyosiform erythroderma
epidermolytic hyperkeratosis (EHK) clinical
epidermolytic hyperkeratosis (EHK) path
epidermolytic hyperkeratosis (EHK) pathogenesis/genetics
Autosomal recessive ichthyosis 2 subtypes–clinical
1) congenital ichthyosiform erythroderma:
- less severe
- fine white scales, significant erythroderma, improves with puberty
2) lamellar ichthyosis
- large, platelike scales, severe ectropion, only miild erythroderma
+palms/soles, flexural surfaces involved in both
Autosomal recessive ichthyosis genetics/pathogenesis
heterogeneous from family to family
CHILD syndrome clinical
CHILD syndrome mnemonic
Congenital Hemidysplasia with Ichthyosiform erythrodermal and Limb Defects
CHILD syndrome genetics
- all cases females
CHILD syndrome pathogenesis
- mutations in genes encoding enzymes that convert lanosterol to cholesterol
CHILD syndrome path
Harlequin ichthyosis clinical/inheritance
Harlequin ichthyosis path
Harlequin ichthyosis genetics