title: Netherton syndrome: disease expression and spectrum of SPINK5 mutations in 21 families.
abstract: Netherton syndrome is a severe autosomal recessive skin disorder characterized by congenital erythroderma, a specific hair-shaft abnormality, and atopic manifestations with high IgE levels. Recently, we identified SPINK5, which encodes the serine protease inhibitor Kazal-type 5 protein (LEKTI), as the defective gene in Netherton syndrome. Here we describe the intron-exon organization of the gene and characterize the SPINK5 mutations in patients from 21 families of different geographic origin, using denaturing high performance liquid chromatography and direct sequencing. We identified 18 mutations, of which 13 were novel and seven (39%) were recurrent. The majority of the mutations were clustered between exons 1-8 and exons 21-26. They comprised four nonsense mutations (22%), eight frameshift insertions or deletions (44%), and six splice-site defects (33%). All mutations predict the formation of premature termination codons. Northern blot analysis showed variable reduction of SPINK5 mutant transcript levels, suggesting variable efficiency of nonsense-mediated mRNA decay. Seven patients were homozygotes, eight were compound heterozygotes, and five were heterozygotes with only one identifiable SPINK5 mutation. Five mutations, one of which resulted in perinatal lethal disease in three families, were associated with certain ethnic groups. We also describe 45 intragenic polymorphisms in the patients studied. The clinical features of erythroderma, trichorrhexis invaginata, and atopic manifestations were present in the majority of affected individuals and ichthyosis linearis circumflexa was seen in 12 out of 24 patients. Interfamilial and intrafamilial variation in disease severity was observed, with no clear correlation between mutations and phenotype, suggesting that the degree of severity may be affected by other factors.
authors.affiliation: Wellcome Trust Center for Human Genetics, Oxford, UK.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Bitoun
authors.forename: Stéphane
authors.initials: S
authors.lastname: Chavanas
authors.forename: Alan D
authors.initials: AD
authors.lastname: Irvine
authors.forename: Lorne
authors.initials: L
authors.lastname: Lonie
authors.forename: Christine
authors.initials: C
authors.lastname: Bodemer
authors.forename: Mauro
authors.initials: M
authors.lastname: Paradisi
authors.forename: Dominique
authors.initials: D
authors.lastname: Hamel-Teillac
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Ansai
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Mitsuhashi
authors.forename: Alain
authors.initials: A
authors.lastname: Taïeb
authors.forename: Yves
authors.initials: Y
authors.lastname: de Prost
authors.forename: Giovanna
authors.initials: G
authors.lastname: Zambruno
authors.forename: John I
authors.initials: JI
authors.lastname: Harper
authors.forename: Alain
authors.initials: A
authors.lastname: Hovnanian
mesh_terms: D000293:Adolescent; D000328:Adult; D002352:Carrier Proteins; D002648:Child; D002675:Child, Preschool; D018389:Codon, Nonsense / Q000235:genetics; D000013:Congenital Abnormalities / Q000235:genetics; D004251:DNA Transposable Elements; D005091:Exons / Q000235:genetics; D017353:Gene Deletion; D016678:Genome; D005838:Genotype; D006197:Hair / Q000002:abnormalities*; D006801:Humans; D006967:Hypersensitivity / Q000235:genetics*; D016113:Ichthyosiform Erythroderma, Congenital / Q000235:genetics*; D007223:Infant; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics; D053491:Proteinase Inhibitory Proteins, Secretory; D022821:RNA Splice Sites / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D000074163:Serine Peptidase Inhibitor Kazal-Type 5; D015842:Serine Proteinase Inhibitors / Q000235:genetics*; D013577:Syndrome
chemical_list: D002352:Carrier Proteins; D018389:Codon, Nonsense; D004251:DNA Transposable Elements; D053491:Proteinase Inhibitory Proteins, Secretory; D022821:RNA Splice Sites; D012333:RNA, Messenger; C120650:SPINK5 protein, human; D000074163:Serine Peptidase Inhibitor Kazal-Type 5; D015842:Serine Proteinase Inhibitors