A new SPINK5 mutation in a patient with Netherton syndrome: a case report

Netherton Syndrome Caused by Heterozygous Frameshift Mutation Combined with Homozygous c.1258A>G Polymorphism in SPINK5 Gene

Netherton syndrome (NS) is a rare autosomal recessive disorder caused by SPINK5 mutations, resulting in a deficiency in its processed protein LEKTI. It is clinically characterized by the triad of congenital ichthyosis, atopic diathesis, and hair shaft abnormalities. The SPINK5 (NM_006846.4): c.1258A>G polymorphism (rs2303067) shows a significant association with atopy and atopic dermatitis (AD), which share several clinical features with NS. We describe an NS patient, initially misdiagnosed with severe AD, who carried the heterozygous frameshift (null) mutation (NM_006846.4): c.957_960dup combined with homozygous rs2303067 in the SPINK5 gene. Histopathological examination confirmed the diagnosis, whereas an immunohistochemical study showed normal epidermal expression of LEKTI, despite the genetic findings. Our results corroborate the hypothesis that haploinsufficiency of SPINK5, in the presence of a SPINK5 null heterozygous mutation in combination with homozygous SPINK5 rs2303067 polymorphism, can be causative of an NS phenotype, impairing the function of LEKTI despite its normal expression. Due to the clinical overlap between NS and AD, we suggest performing SPINK5 genetic testing to search for the SPINK5 (NM_006846.4): c.1258A>G polymorphism (rs2303067) and ensure a correct diagnosis, mainly in doubtful cases.

A novel mutation in SPINK5 gene underlies a case of atypical Netherton syndrome

Netherton syndrome (NS, OMIM #256500) is a rare autosomal recessive disease characterized by a triad of congenital ichthyosiform erythroderma (CIE) or ichthyosis linearis circumflexa (ILC), trichorrhexis invaginata (TI), and atopic predisposition. The disease is caused by a mutation in the SPINK5 gene (serine protease inhibitor of Kazal type 5) encoding LEKTI (lymphoepithelial Kazal type-related inhibitor). We performed whole-exome sequencing on one Chinese NS family and made genotype–phenotype correlation analysis on the patients clinically diagnosed with NS or congenital ichthyosis erythroderma. We identified a novel frameshift mutation c.2474_2475del (p.Glu825Glyfs*2) in the SPINK5 gene. The N-terminal mutations of LEKTI cause a severer phenotype, while the C-terminal mutations of LEKT1 are related to a milder phenotype. Our findings suggest that Netherton syndrome may be underestimated clinically, and our findings further expand the reservoir of SPINK5 mutations in Netherton syndrome.

A novel SPINK5 donor splice site variant in a child with Netherton syndrome

BACKGROUND

Netherton syndrome (NS) is a genodermatosis caused by loss-of-function mutations in SPINK5, resulting in aberrant LEKTI expression.

METHOD

Next-generation sequencing of SPINK5 (NM_001127698.1) was carried out and functional studies were performed by immunofluorescence microscopy of a lesional skin biopsy using anti-LEKTI antibodies.

RESULTS

We describe a novel SPINK5 likely pathogenic donor splice site variant (NM_001127698.1:c.2015+5G>A) in a patient with NS and confirm its functional significance by demonstrating complete loss of LEKTI expression in lesional skin by immunofluorescence analysis.

CONCLUSION

The 2015+5G>A is a novel, likely pathogenic variant in NS. Herein we review and assimilate documented SPINK5 pathogenic variants and discuss possible genotype-phenotype associations in NS.

A New Splice-site Mutation of SPINK5 Gene in the Netherton Syndrome with Different Clinical Features: A Case Report

Netherton syndrome (NS) is a rare genodermatosis characterized by the triad of ichthyosiform erythroderma, hair shaft abnormality and an atopic diathesis. We report a case of a 20-year-old male patient presented with pruritus, decreased sweat secretion and generalized erythema on his body. Netherton syndrome is caused by mutations in the SPINK5 gene that is a crucial role for epidermal barrier function in the skin. Different clinical and phenotypical features can occur based on various LEKTI-domains mutations. Diagnosis is made by the atopic story, hair shaft abnormality, cutaneous lesions and identification of the SPINK5 gene mutation. In our patient, we detected a new splice site mutation in the SPINK5 gene and pili annulati as hair abnormality. Affected patients are usually misdiagnosed because of cutaneous lesions such as atopic dermatitis. Therefore, each clinical finding should be evaluated together. We aimed to present a case with a new SPINK5 gene mutation and different clinical features in NS.