Chapter 47 - The Ichthyoses Flashcards by Caryl Lyca Dematawaran

MODE OF INHERITANCE

Ichthyosis vulgaris

Autosomal Semidominant

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MODE OF INHERITANCE

Epidermolytic ichthyosis

Autosomal Dominant

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MODE OF INHERITANCE

Superficial epidermolytic

Autosomal Dominant

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MODE OF INHERITANCE

Erythrokeratodermia variabilis

Autosomal Dominant

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MODE OF INHERITANCE

Progressive symmetric erythrokeratoderma

Autosomal Dominant

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MODE OF INHERITANCE

Keratitis–ichthyosis–deafness (KID) syndrome

Autosomal Dominant

Recessive has been reported

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TABLE 47-1
Features of Selected Ichthyoses with Dominant Inheritance

ONSET

Ichthyosis vulgaris

Infancy or childhood

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TABLE 47-1
Features of Selected Ichthyoses with Dominant Inheritance

ONSET

Epidermolytic ichthyosis

Birth

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TABLE 47-1
Features of Selected Ichthyoses with Dominant Inheritance

ONSET

Superficial epidermolytic

Birth

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TABLE 47-1
Features of Selected Ichthyoses with Dominant Inheritance

ONSET

Erythrokeratodermia variabilis, Generalized type

Birth

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TABLE 47-1
Features of Selected Ichthyoses with Dominant Inheritance

ONSET

Erythrokeratodermia variabilis, Localized type

Variable

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TABLE 47-1
Features of Selected Ichthyoses with Dominant Inheritance

ONSET

Progressive symmetric
erythrokeratoderma

Shortly after birth

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TABLE 47-1
Features of Selected Ichthyoses with Dominant Inheritance

ONSET

Keratitis–ichthyosis–deafness (KID) syndrome

Birth/infancy

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TABLE 47-1
Features of Selected Ichthyoses with Dominant Inheritance

DIAGNOSIS

Fine or centrally tacked-down scale with superficial fissuring; relative flexural sparing, worse on lower extremities; hyperlinear palms and soles

Ichthyosis vulgaris

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TABLE 47-1
Features of Selected Ichthyoses with Dominant Inheritance

DIAGNOSIS

Heterogeneous; may have verrucous, firm, hyperkeratotic (hystrix) spines, often linearly arrayed in flexural creases; blisters; may have erythroderma and/or palmar/plantar keratoderma

Epidermolytic ichthyosis

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TABLE 47-1
Features of Selected Ichthyoses with Dominant Inheritance

DIAGNOSIS

Redness and blistering at birth; later develop hyperkeratosis, accentuated over flexures; mauserung (molting): collarette-like lesion where uppermost epidermis has been lost

Superficial epidermolytic ichthyosis

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TABLE 47-1
Features of Selected Ichthyoses with Dominant Inheritance

DIAGNOSIS

Generalized hyperkeratosis and figurate, migratory red patches

Erythrokeratodermia variabilis, Generalized type

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TABLE 47-1
Features of Selected Ichthyoses with Dominant Inheritance

DIAGNOSIS

Localized hyperkeratotic plaques with figurate, migratory red patches

Erythrokeratodermia variabilis, Localized type

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TABLE 47-1
Features of Selected Ichthyoses with Dominant Inheritance

DIAGNOSIS

Erythematous, scaly plaques, symmetrically distributed over extremities, buttocks, and face; stabilize in early childhood; trunk tends to be spared

Progressive symmetric erythrokeratoderma

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TABLE 47-1
Features of Selected Ichthyoses with Dominant Inheritance

DIAGNOSIS

Progressive corneal opacification; either mild generalized hyperkeratosis or discrete erythematous plaques, which may be symmetric; neurosensory deafness

Keratitis–ichthyosis–deafness (KID) syndrome

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TABLE 47-1
Features of Selected Ichthyoses with Dominant Inheritance

DIAGNOSIS

ASSOCIATED FEATURES
Keratosis pilaris; atopy

Ichthyosis vulgaris

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TABLE 47-1
Features of Selected Ichthyoses with Dominant Inheritance

DIAGNOSIS

ASSOCIATED FEATURES
Frequent skin infections; characteristic pungent odor

Epidermolytic ichthyosis

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TABLE 47-1
Features of Selected Ichthyoses with Dominant Inheritance

DIAGNOSIS

ASSOCIATED FEATURES
Red patches move over minutes to hours; may be triggered by changes in temperature

Erythrokeratodermia variabilis, Generalized type

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TABLE 47-1
Features of Selected Ichthyoses with Dominant Inheritance

DIAGNOSIS

ASSOCIATED FEATURES
Hyperkeratotic plaques may be induced by trauma; considerable intrafamilial variability

Erythrokeratodermia variabilis, Localized type

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TABLE 47-1 Features of Selected Ichthyoses with Dominant Inheritance DIAGNOSIS ASSOCIATED FEATURES Follicular hyperkeratosis, scarring alopecia, dystrophic nails, susceptibility to infection

Keratitis–ichthyosis–deafness (KID) syndrome

TABLE 47-1 Features of Selected Ichthyoses with Dominant Inheritance GENE Ichthyosis vulgaris

FLG

TABLE 47-1 Features of Selected Ichthyoses with Dominant Inheritance GENE Epidermolytic ichthyosis

KRT1, KRT10

TABLE 47-1 Features of Selected Ichthyoses with Dominant Inheritance GENE Superficial epidermolytic ichthyosis

KRT2

TABLE 47-1 Features of Selected Ichthyoses with Dominant Inheritance GENE Erythrokeratodermia variabilis, Generalized type

GJB3, GJB4, GJA

TABLE 47-1 Features of Selected Ichthyoses with Dominant Inheritance GENE Progressive symmetric erythrokeratoderma

LOR, GJB4

TABLE 47-1 Features of Selected Ichthyoses with Dominant Inheritance GENE Keratitis–ichthyosis–deafness (KID) syndrome

GJB2

TABLE 47-1 Features of Selected Ichthyoses with Dominant Inheritance PROTEIN Ichthyosis vulgaris

Absence of filaggrin

TABLE 47-1 Features of Selected Ichthyoses with Dominant Inheritance PROTEIN Epidermolytic ichthyosis

Keratin 1 or 10

TABLE 47-1 Features of Selected Ichthyoses with Dominant Inheritance PROTEIN Superficial epidermolytic ichthyosis

Keratin 2, which is expressed in superficial epidermis

TABLE 47-1 Features of Selected Ichthyoses with Dominant Inheritance PROTEIN Erythrokeratodermia variabilis, Generalized type

Connexin 30.3, 31, or 43; connexins form gap junction channels between cells

TABLE 47-1 Features of Selected Ichthyoses with Dominant Inheritance PROTEIN Progressive symmetric erythrokeratoderma

Loricrin, connexin 30.3

TABLE 47-1 Features of Selected Ichthyoses with Dominant Inheritance PROTEIN Keratitis–ichthyosis–deafness (KID) syndrome

Connexin 26; connexins form gap junction channels between cells

TABLE 47-1 Features of Selected Ichthyoses with Dominant Inheritance PROTEIN FUNCTION Uncertain—may aggregate keratin filaments and be a precursor to stratum corneum humectants

Filaggrin Ichthyosis vulgaris

TABLE 47-1 Features of Selected Ichthyoses with Dominant Inheritance PROTEIN FUNCTION Structural protein abnormality leading to keratin intermediate filament dysfunction—epidermal fragility

Keratin 1, 2, 10 Epidermolytic ichthyosis Superficial epidermolytic ichthyosis

TABLE 47-1 Features of Selected Ichthyoses with Dominant Inheritance PROTEIN FUNCTION Intercellular communication

Connexin Erythrokeratodermia variabilis, Generalized type Progressive symmetric erythrokeratoderma Keratitis–ichthyosis–deafness (KID) syndrome

TABLE 47-1 Features of Selected Ichthyoses with Dominant Inheritance PROTEIN FUNCTION Cornified envelope precursor

Loricrin Progressive symmetric erythrokeratoderma

MODE OF INHERITANCE X-linked recessive ichthyosis

X-linked recessive

MODE OF INHERITANCE Chondrodysplasia punctata

X-linked recessive

MODE OF INHERITANCE Chondrodysplasia punctata (Conradi-Hünermann-Happle syndrome)

X-linked dominant

CHILD syndrome

X-linked

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance ONSET X-linked recessive ichthyosis

Birth or infancy

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance ONSET CHILD syndrome

Birth

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance ONSET Chondrodysplasia punctata X-linked recessive

Birth

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance ONSET X-linked dominant chondrodysplasia punctata (Conradi-Hünermann-Happle syndrome)

Birth

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance DIAGNOSIS Fine to large scales; comma-shaped corneal opacities on posterior capsule

X-linked recessive ichthyosis

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance DIAGNOSIS May begin as erythroderma, linear or whorled atrophic areas or hyperkeratosis, alopecia, skeletal abnormalities, short stature

Chondrodysplasia punctata X-linked recessive

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance DIAGNOSIS Congenital ichthyosiform erythroderma at birth; clears and is replaced by linear hyperkeratosis, follicular atrophoderma and pigmentary abnormalities, and stippled calcifications on radiographs

X-linked dominant chondrodysplasia punctata (Conradi-Hünermann-Happle syndrome)

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance DIAGNOSIS Congenital hemidysplasia, ichthyosiform erythroderma, limb defects

CHILD syndrome

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance DIAGNOSIS ASSOCIATED FEATURES Cryptorchidism; female carriers may have corneal opacities and delay of onset or progression of labor in affected pregnancies

X-linked recessive ichthyosis

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance DIAGNOSIS ASSOCIATED FEATURES Cataracts, deafness

Chondrodysplasia punctata X-linked recessive

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance DIAGNOSIS ASSOCIATED FEATURES Occurs almost exclusively in females; hair shaft abnormalities, short stature, cataracts

X-linked dominant chondrodysplasia punctata (Conradi-Hünermann-Happle syndrome)

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance DIAGNOSIS ASSOCIATED FEATURES Occurs almost exclusively in females

CHILD syndrome

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance GENE X-linked recessive ichthyosis

STS

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance GENE Chondrodysplasia punctata X-linked recessive

ARSE

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance GENE X-linked dominant chondrodysplasia punctata (Conradi-Hünermann-Happle syndrome)

EBP

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance GENE CHILD syndrome

NSDHL; EBP reported

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance PROTEIN X-linked recessive ichthyosis

Steroid sulfatase

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance PROTEIN Chondrodysplasia punctata X-linked recessive

Arylsulfatase E

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance PROTEIN X-linked dominant chondrodysplasia punctata (Conradi-Hünermann-Happle syndrome)

EBP, also known as 3B-hydroxysteroid-8,7-isomerase

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance PROTEIN CHILD syndrome

NSDHL (3B-hydroxysteroid dehydrogenase); EBP reported

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance PROTEIN FUNCTION Lipid metabolism—abnormal cholesterol metabolism with accumulation of cholesterol sulfate

Steroid sulfatase X-linked recessive ichthyosis

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance PROTEIN FUNCTION Lipid metabolism—ill defined: failure of hydrolysis of sulfate ester bonds

Arylsulfatase E Chondrodysplasia punctata X-linked recessive

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance PROTEIN FUNCTION Lipid metabolism—abnormal cholesterol biosynthesis

EBP X-linked dominant chondrodysplasia punctata (Conradi-Hünermann-Happle syndrome)

TABLE 47-2 Features of Selected Ichthyoses with X-linked Inheritance PROTEIN FUNCTION Lipid metabolism—postsqualene cholesterol biosynthesis

NSDHL CHILD syndrome

MODE OF INHERITANCE Autosomal recessive congenital ichthyosis/Lamellar ichthyosis (ARCI/LI)

Autosomal Recessive

MODE OF INHERITANCE Autosomal recessive congenital ichthyosis/Congenital ichthyosiform erythroderma (ARCI/CIE)

Autosomal Recessive

MODE OF INHERITANCE Harlequin ichthyosis

Autosomal Recessive

MODE OF INHERITANCE Ichthyosis prematurity syndrome

Autosomal Recessive

MODE OF INHERITANCE Netherton syndrome

Autosomal Recessive

MODE OF INHERITANCE Sjögren-Larsson syndrome

Autosomal Recessive

MODE OF INHERITANCE Refsum disease

Autosomal Recessive

MODE OF INHERITANCE Trichothiodystrophy (Tay syndrome)

Autosomal Recessive

MODE OF INHERITANCE Chanarin–Dorfman syndrome (neutral lipid storage disease)

Autosomal Recessive

MODE OF INHERITANCE Neonatal ichthyosis–sclerosing cholangitis syndrome

Autosomal Recessive

MODE OF INHERITANCE Multiple sulfatase deficiency

Autosomal Recessive

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance ONSET Autosomal recessive congenital ichthyosis (ARCI)

Birth; often collodion presentation

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance ONSET Harlequin ichthyosis

Birth

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance ONSET Ichthyosis prematurity syndrome

Birth

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance ONSET Netherton syndrome

Birth

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance ONSET Sjögren-Larsson syndrome

Ichthyosis apparent at birth

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance ONSET Refsum disease

Ichthyosis develops years after birth

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance ONSET Trichothiodystrophy (Tay syndrome)

Some have ichthyosis, which may be apparent at birth; may have collodion presentation

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance ONSET Chanarin–Dorfman syndrome (neutral lipid storage disease)

Birth; may have collodion membrane

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance ONSET Neonatal ichthyosis–sclerosing cholangitis syndrome

Birth

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance ONSET Multiple sulfatase deficiency

Birth

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS Large, platelike, brown scale over most of the body; accentuated on lower extremities; ectropion, eclabium, and alopecia, palmar/ plantar involvement varies

Autosomal recessive congenital ichthyosis/Lamellar ichthyosis (ARCI/LI)

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS Fine, white scale; generalized erythroderma; palmar/plantar involvement varies

Autosomal recessive congenital ichthyosis/Congenital ichthyosiform erythroderma (ARCI/CIE)

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS Markedly thickened skin with geometric, deep fissures; at birth survivors develop severe erythroderma

Harlequin ichthyosis

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS Premature delivery of infants with erythrodermic, edematous, caseous scaling skin resembling excessive vernix caseosa, evolves into dry, scaly skin with follicular accentuation with signs of atopy

Ichthyosis prematurity syndrome

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS Ichthyosis linearis circumflexa or similar to congenital ichthyosiform erythroderma; trichorrhexis invaginata

Netherton syndrome

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS Generalized fine to coarse hyperkeratosis; spastic diplegia; mental retardation; retinal glistening white dots

Sjögren-Larsson syndrome

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS Progressive neurologic dysfunction; skeletal, cardiac, and renal abnormalities

Refsum disease

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS Brittle hair, photosensitivity, short stature, ichthyosis, intellectual impairment, microcephaly, recurrent infections

Trichothiodystrophy (Tay syndrome)

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS Generalized scaling, resembles congenital ichthyosiform erythroderma; variable extracutaneous involvement: cataracts, decreased hearing, psychomotor delay

Chanarin–Dorfman syndrome (neutral lipid storage disease)

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS Neonatal cholestatic jaundice, mild ichthyosis with fine, white scales

Neonatal ichthyosis–sclerosing cholangitis syndrome

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS Ichthyosis resembling X-linked recessive

Multiple sulfatase deficiency

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS ASSOCIATED FEATURES Heat intolerance

Autosomal recessive congenital ichthyosis (ARCI)

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS ASSOCIATED FEATURES Restricted respiration, feeding; neonatal sepsis; often leads to neonatal death; failure to thrive

Harlequin ichthyosis

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS ASSOCIATED FEATURES Respiratory distress, and transient peripheral eosinophilia; the respiratory signs resolve

Ichthyosis prematurity syndrome

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS ASSOCIATED FEATURES Atopy; high serum levels of IgE; may have aminoaciduria; failure to thrive

Netherton syndrome

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS ASSOCIATED FEATURES Short stature, seizures

Sjögren-Larsson syndrome

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS ASSOCIATED FEATURES Retinitis pigmentosa, elevated plasma phytanic acid

Refsum disease

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS ASSOCIATED FEATURES Abnormally low sulfur content of hair

Trichothiodystrophy (Tay syndrome)

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS ASSOCIATED FEATURES Severe pruritus; neurologic abnormalities; hepatic abnormalities; lipid droplets in circulating leukocytes

Chanarin–Dorfman syndrome (neutral lipid storage disease)

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS ASSOCIATED FEATURES Scarring alopecia of the scalp and eyebrows, enamel dysplasia

Neonatal ichthyosis–sclerosing cholangitis syndrome

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance DIAGNOSIS ASSOCIATED FEATURES Neurologic deterioration; skeletal abnormalities; facial dysmorphism

Multiple sulfatase deficiency

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance GENE Autosomal recessive congenital ichthyosis (ARCI)

ALOXE3 ALOX12B NIPAL4 CYP4F22 PNPLA1, CERS3, SDR9C7, SULT2B1

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance GENE Harlequin ichthyosis

ABCA12

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance GENE Ichthyosis prematurity syndrome

FATP4 (SLC27)

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance GENE Netherton syndrome

SPINK5

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance GENE Sjögren-Larsson syndrome

FALDH (ALDH10, ALDH3A2)

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance GENE Refsum disease

Most PAHX; PEX 7 also reported

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance GENE Trichothiodystrophy (Tay syndrome)

Majority have defect in ERCC2 (XPD). A few have mutations in ERCC3 (XPB), GTF2H5 (TTDA), or TTDN1.

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance GENE Chanarin–Dorfman syndrome (neutral lipid storage disease)

ABHD5

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance GENE Neonatal ichthyosis–sclerosing cholangitis syndrome

CLDN1

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance GENE Multiple sulfatase deficiency

SUMF1

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance PROTEIN Autosomal recessive congenital ichthyosis (ARCI)

Lipoxygenase 3 12(R)-lipoxygenase E3 Magnesium transporter NIPA4 Cytochrome P450 family 4 subfamily F member 22 Patatin like phospholipase domain containing 1, Ceramide synthase 3, Short chain dehydrogenase/reductase family 9C member 7, Sulfotransferase family 2B member 1

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance PROTEIN Harlequin ichthyosis

ATP-binding cassette, subfamily A, member 12

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance PROTEIN Ichthyosis prematurity syndrome

Fatty acid transport protein 4

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance PROTEIN Netherton syndrome

LEKTI (a serine protease inhibitor)

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance PROTEIN Sjögren-Larsson syndrome

Fatty aldehyde dehydrogenase

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance PROTEIN Refsum disease

Phytanoyl-CoA hydroxylase (PhyH)

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance PROTEIN Trichothiodystrophy (Tay syndrome)

Most XPD, XPB, TTDA, or TTDN1 in a few

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance PROTEIN Chanarin–Dorfman syndrome (neutral lipid storage disease)

Abhydrolase domain-containing protein 5

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance PROTEIN Neonatal ichthyosis–sclerosing cholangitis syndrome

Claudin 1

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance PROTEIN Multiple sulfatase deficiency

C alpha-formylglycine generating enzyme

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance PROTEIN FUNCTION Lipid metabolism—membrane transport, abnormality of lipid metabolism

ATP-binding cassette, subfamily A, member 12 Harlequin ichthyosis

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance PROTEIN FUNCTION Lipid metabolism—fatty acid transport

Fatty acid transport protein 4 Ichthyosis prematurity syndrome

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance PROTEIN FUNCTION Protein metabolism—inhibits degradation of desmosomal proteins and perhaps filaggrin in stratum corneum

LEKTI Netherton syndrome

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance PROTEIN FUNCTION Lipid metabolism—fatty aldehyde metabolism

Fatty aldehyde dehydrogenase Sjögren-Larsson syndrome

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance PROTEIN FUNCTION Peroxisome abnormality—deficiency of phytanic acid catabolism; results in phytanic acid accumulation

Phytanoyl-CoA hydroxylase (PhyH) Refsum disease

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance PROTEIN FUNCTION Components of transcription factor TFIIH

Most XPD. XPB, TTDA, or TTDN1 in a few Trichothiodystrophy (Tay syndrome)

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance PROTEIN FUNCTION Lipid metabolism—activates adipose-triglyceride lipase for lipolysis of triglycerides

Abhydrolase domain-containing protein 5 Chanarin–Dorfman syndrome (neutral lipid storage disease)

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance PROTEIN FUNCTION Tight junction

Claudin 1 Neonatal ichthyosis–sclerosing cholangitis syndrome

TABLE 47-3 Features of Selected Ichthyoses with Autosomal Recessive Inheritance PROTEIN FUNCTION Generates catalytic residue in active site of eukaryotic sulfatases

C alpha-formylglycine generating enzyme Multiple sulfatase deficiency