ichtyosis

Ichthyosis

DISEASE CARD

Disease group	Disorders of cornification
DISEASE NAME	Ichthyosis
Estimated prevalence	1:200

Ichthyoses are determined as Mendelian disorders of cornification (MeDOC) that are characterized by generalized scaling of the skin. From a pathophysiological perspective, they are associated with abnormal differentiation and/or abnormal desquamation (retention hyperkeratosis versus hyperproliferative hyperkeratosis/epidermal hyperplasia)

In a consensus conference in 2009, a new classification system and terminology has been established for ichthyoses.¹ In two main categories, non-syndromic forms (phenotype restricted to the skin) are distinguished from syndromic forms (involvement of other organs). The onset of the disease is in almost all ichthyoses (except Refsum disease) at birth or in early childhood.

Classification

Inherited ichthyosis – nonsyndromic forms			Mode of inheritance	Gene(s)
Common ichthyoses	Ichthyosis vulgaris (IV) [146700]		A(s)D	FLG
Common ichthyoses	Recessive X-linked ichthyosis (XRI) – non syndromic presentation [308100]		XR	STS
Autosomal recessive congenital ichthyosis (ARCI)	Major types	Harlequin ichthyosis (HI) [242500]	AR	ABCA12
	Major types	Lamellar ichthyosis (LI), Congenital ichthyosiform erythroderma (CIE) [242300] [242100] [601277] [606545] [604777] [612281] [613943] [615023] [615024] [602400] [617320] [617571] [617574]	AR	TGM1, NIPAL4, ALOX12B, ALOXE3, ABCA12, CYP4F22, LIPN, CERS3, PNPLA1, ST14, CASP14, SULT2B1, SDR9C7
	Minor variants	Self-improving congenital ichthyosis [242300] [242100] [606545]	AR	TGM1, ALOX12B, ALOXE3
	Minor variants	Bathing suit ichthyosis (BSI) [242300]	AR	TGM1
Keratinopathic ichthyosis (KPI)	Major types	Epidermolytic ichthyosis (EI) [113800]	AD	KRT1, KRT10
	Major types	Superficial epidermolytic ichthyosis (SEI) [146800]	AD	KRT2
	Minor variants	Annular epidermolytic ichthyosis (AEI) [607602]	AD	KRT1, KRT10
		Ichthyosis Curth-Macklin (ICM) [146590]	AD	KRT1, KRT10
		AR Epidermolytic ichthyosis (AREI) [113800]	AR	KRT10
		Congenital reticular ichthyosiform erythroderma (CRIE), Ichthyosis with confetti (IWC) [609165]	AD	KRT10, KRT1
		Epidermolytic naevi [113800]	Somatic mutations	KRT1, KRT10
Other forms		Loricin keratoderma (LK) [604117]	AD	LOR
		Erythrokeratodermia variabilis (EKV) [133200]	AD	GJB3, GJB4
		Peeling skin disease (PSD) [270300]	AR	CDSN
		Keratosis linearis – ichthyosis congenital – keratoderma (KLICK) [601952]	AR	POMP
		Exfoliative ichthyosis [607936]	AR	CSTA

^{A(s)D = autosomal semidominant; AD = autosomal dominant; XR = x-linked recessive; AR = autosomal recessive; OMIM in [ ] http://www.omim.org}

Inherited ichthyosis – syndromic forms			Mode of inheritance	Gene(s)
X-linked ichthyosis syndromes	RXLI – syndromic presentation [308100]		XLR	STS (and others)
	Ichthyosis follicularis-atrichia-photophobia (IFAP) syndrome [308205]		XLR	MBTPS2
	Conradi-Hünermann-Happle syndrome (CDPX2) [302960]		XLD	EBP
Autosomal ichthyosis syndromes (with…)	Prominent hair abnormalities	Netherton syndrome (NS) [256500]	AR	SPINK5
		Ichthyosis-hypotrichosis syndrome (IHS) [602400]	AR	ST14
		Ichthyosis-hypotrichosis-sclerosing cholangitis syndrome (IHSC) [607626]	AR	CLDN1
		Trichothiodystrophy (TTD) [601675] [616390] [616395]	AR	ERCC2/XPD, ERCC3/XPB, GTF2H5/TTDA
	Prominent neurologic signs	Sjögren-Larsson syndrome (SLS) [270200]	AR	ALDH3A2
		Refsum syndrome (RS) [266500]	AR	PHYH, PEX7
		Mental retardation-enteropathy-deafness-neuropathy-ichthyosis-keratodermia syndrome (MEDNIK) [609313]	AR	AP1S1
		Ichthyotic keratoderma, spasticity, hypomyelination, and dysmorphic features (IKSHD) [618527]	AD	ELOVL1
		Ichthyosis, spastic quadriplegia, mental retardation (ISQMR) [614457]	AR	ELOVL4
	Fatal disease course	Gaucher syndrome type 2 (GS) [230900]	AR	GBA
		Multiple sulfatase deficiency (MSD) [272200]	AR	SUMF1
		Cerebral dysgenesis-neuropathy-ichthyosis-palmoplantar keratoderma syndrome (CEDNIK) [609528]	AR	SNAP29
		Arthrogryposis-renal dysfunction-cholestasis syndrome (ARC) [208085]	AR	VPS33B
	Other associated signs	Keratitis-Ichthyosis-Deafness syndrome (KID) [148210]	AD	GJB2, GJB4
		Keratitis-Ichthyosis-Deafness autosomal recessive (KIDAR) [242150]	AR	AP1B1
		Neutral lipid storage disease with ichthyosis / Chanarin-Dorfman syndrome (CDS) [275630]	AR	ABHD5, CGI-58
		Severe dermatitis‐multiple allergies‐metabolic wasting syndrome (SAM) [615508]	AR/AD	DSG1, DSP
		Ichthyosis prematurity syndrome (IPS) [608649]	AR	SLC27A4

^{A(s)D = autosomal semidominant; AD = autosomal dominant; XR = x-linked recessive; AR = autosomal recessive; OMIM in [ ] http://www.omim.org}

References

Oji V, Tadini G, Akiyama M, Blanchet Bardon C, Bodemer C, Bourrat E, et al. Revised nomenclature and classification of inherited ichthyoses: results of the First Ichthyosis Consensus Conference in Sorèze 2009. J Am Acad Dermatol. 2010;63(4):607-641.

Ichthyosis

Related Topics

DISEASE CARD

Classification

A(s)D = autosomal semidominant; AD = autosomal dominant; XR = x-linked recessive; AR = autosomal recessive; OMIM in [ ] http://www.omim.org

A(s)D = autosomal semidominant; AD = autosomal dominant; XR = x-linked recessive; AR = autosomal recessive; OMIM in [ ] http://www.omim.org

References

^{A(s)D = autosomal semidominant; AD = autosomal dominant; XR = x-linked recessive; AR = autosomal recessive; OMIM in [ ] http://www.omim.org}

^{A(s)D = autosomal semidominant; AD = autosomal dominant; XR = x-linked recessive; AR = autosomal recessive; OMIM in [ ] http://www.omim.org}