Metabolic cutis laxa syndromes

Abstract

Cutis laxa is a rare skin disorder characterized by wrinkled, redundant, inelastic and sagging skin due to defective synthesis of elastic fibers and other proteins of the extracellular matrix. Wrinkled, inelastic skin occurs in many cases as an acquired condition. Syndromic forms of cutis laxa, however, are caused by diverse genetic defects, mostly coding for structural extracellular matrix proteins. Surprisingly a number of metabolic disorders have been also found to be associated with inherited cutis laxa. Menkes disease was the first metabolic disease reported with old-looking, wrinkled skin. Cutis laxa has recently been found in patients with abnormal glycosylation. The discovery of the COG7 defect in patients with wrinkled, inelastic skin was the first genetic link with the Congenital Disorders of Glycosylation (CDG). Since then several inborn errors of metabolism with cutis laxa have been described with variable severity. These include P5CS, ATP6V0A2-CDG and PYCR1 defects. In spite of the evolving number of cutis laxa-related diseases a large part of the cases remain genetically unsolved. In metabolic cutis laxa syndromes the clinical and laboratory features might partially overlap, however there are some distinct, discriminative features. In this review on metabolic diseases causing cutis laxa we offer a practical approach for the differential diagnosis of metabolic cutis laxa syndromes.

Fig. 1

Genetic defects related to biochemical pathways or inborn errors of metabolism in patients with cutis laxa and their suggested pathomechanism

Fig. 2

Metabolic pathways related to P5CS and PYCR1 defects

Fig. 3

Cutis laxa in a patient with ARCL2 demonstrating sagging truncal and abdominal skin (a), characteristic facial features and microcephaly in a patient with COG7-CDG (b), kinky, hypopigmented hair in X-linked cutis laxa syndrome (c) and downslanting palpebral fissures and sagging chin in patient with ATP6V0A2-CDG (d)