Long-term change of disease behavior in Papillon-Lefèvre syndrome: Seven years follow-up

Cathepsin C in health and disease: from structural insights to therapeutic prospects

Cathepsin C (CTSC) is a lysosomal cysteine protease constitutively expressed at high levels in the lung, kidney, liver, and spleen. It plays a key role in the activation of serine proteases in cytotoxic T cells, natural killer cells (granzymes A and B), mast cells (chymase and tryptase) and neutrophils (cathepsin G, neutrophil elastase, proteinase 3) underscoring its pivotal significance in immune and inflammatory defenses. Here, we comprehensively review the structural attributes, synthesis, and function of CTSC, with a focus on its variants implicated in the etiopathology of several syndromes associated with neutrophil serine proteases, including Papillon-Lefevre syndrome (PLS), Haim-Munk Syndrome (HMS), and aggressive periodontitis (AP). These syndromes are characterized by palmoplantar hyperkeratosis, and early-onset periodontitis (severe gum disease) resulting in premature tooth loss. Due to the critical role played by CTSC in these and several other conditions it is being explored as a potential therapeutic target for autoimmune and inflammatory disorders. The review also discusses in depth the gene variants of CTSC, and in particular their postulated association with chronic obstructive pulmonary disease (COPD), COVID-19, various cancers, anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, sudden cardiac death (SCD), atherosclerotic vascular disease, and neuroinflammatory disease. Finally, the therapeutic potential of CTSC across a range of human diseases is discussed.

"Oral Manifestations of Patients with Inherited Defect in Phagocyte Number or Function" a systematic review

INTRODUCTION

Inherited phagocyte defects are one of the subgroups of primary immunodeficiency diseases (PIDs) with various clinical manifestations. As oral manifestations are common at the early ages, oral practitioners can have a special role in the early diagnosis.

MATERIALS AND METHODS

A comprehensive search was conducted in this systematic review study and data of included studies were categorized into four subgroups of phagocyte defects, including congenital neutropenia, defects of motility, defects of respiratory burst, and other non-lymphoid defects.

RESULTS

Among all phagocyte defects, 12 disorders had reported data for oral manifestations in published articles. A total of 987 cases were included in this study. Periodontitis is one of the most common oral manifestations.

CONCLUSION

There is a need to organize better collaboration between medical doctors and dentists to diagnose and treat patients with phagocyte defects. Regular dental visits and professional oral health care are recommended from the time of the first primary teeth eruption in newborns.

A novel missense variant in cathepsin C gene leads to PLS in a Chinese patient: A case report and literature review

BACKGROUND

Papilon-Lefevre syndrome (PLS; OMIM 245000) is a rare autosomal recessive disease characterized by aggressive periodontitis and palmoplantar keratoderma. The prevalence of PLS in the general population is one to four cases per million. Although the etiology and pathogenic mechanisms underlying PLS remain largely unclear, existing evidence shows loss-of-function mutations of the cathepsin C gene (CTSC; OMIM 602365) could cause PLS. Here we found a novel variant of the CTSC gene in a Chinese PLS family and predicted the effect of the variant on the physic-chemical characters and tertiary structure of the protein.

METHODS

The 1-7 coding exons and exon-intron boundaries of CTSC gene of the proband and her family were amplified and sequenced directly, and Chromas was used to read sequencing files. Furthermore, the PolyPhen-2, PROVEAN, and Mutation Taster were utilized to predict the pathogenicity of the variant. Besides, the physic-chemical and structural characters of the protein were analyzed by ProtParam, ProtScale, and SWISS-MODEL.

RESULTS

Our study identified a novel homozygous variant c.763T>C (p.Cys255Arg) in exon 6 of the CTSC gene, and it was a likely pathogenic variant as predicted by PolyPhen-2, PROVEAN, and Mutation Taster. Moreover, ProtParam and Protscale revealed the variant increased the isoelectric point and hydrophilicity of the protein, and the SWISS-MODEL analysis suggested the variant was located in a critical domain for protein activity.

CONCLUSION

Our study analyzed a Chinese family with PLS and identified a novel missense variant in the CTSC gene. Besides, this study retrospectively summarized 113 variants of CTSC in the world and highlighted the features of 27 CTSC variants in Chinese PLS patients. In addition, this study paid much particular attention to the relationship between CTSC variants and different phenotypes.

[Gene mutational analyses of cathepsin C gene in a family with Papillon-Lefèvre syndrome]

OBJECTIVE

This study aimed to investigate the gene mutational characteristics of cathepsin C (CTSC) gene in a Chinese patient with Papillon-Lefèvre syndrome (PLS) and further confirm the genetic basis for the phenotype of PLS.

METHODS

Peripheral blood samples were obtained from the PLS proband and his family members (his parents and younger brother) for genomic DNA extraction. The coding region and exon boundaries of the CTSC gene were amplified and sequenced by polymerase chain reaction and direct sequencing of DNA.

RESULTS

Compound heterozygous mutations of CTSC gene were identified in the patient. A heterozygous missense mutation occurred in the 800th base of exon 6, and the base T in the base pair was replaced by C (c.800T>C). The encoded amino acid leucine changed to proline (p. L267P). A heterozygous missense mutation occurred in the 1015th base of exon 7, and base C in the base pair was replaced by T (c.1015C>T). The encoded amino acid arginine changed to cysteine (p.R339C). Among the mutations, c.800T>C originated from the mother, c.1015C>T was identified from the father. No mutations were detected in the younger brother.

CONCLUSIONS

Mutations of CTSC gene are responsible for the phenotype of PLS.

[Gene mutational analyses of the cathepsin C gene in families with Papillon-Lefèvre syndrome]

OBJECTIVE

This study aims to investigate the gene mutational characteristics of cathepsin C (CTSC) gene in a Chinese patient with Papillon-Lefèvre syndrome (PLS), then further confirm the genetic basis for the phenotype of PLS, and obtain genetic information that can be used as guide in the diagnosis and treatment of PLS.

METHODS

With their consent, peripheral blood samples were obtained from the proband and his family members (his parents and older sister) for genomic DNA extraction. The coding region and exon/intron boundaries of the CTSC gene were amplified and sequenced using poly-merase chain reaction and direct sequencing of DNA.

RESULTS

Compound heterozygous mutations of CTSC gene were iden-tified in the patient. The proband carries one heterozygous nonsense mutation c.754C>T in exon 5 and one heterozygous missense mutation c.1040A>G in exon 7. Both parents were heterozygous carriers without the clinical symptoms of PLS. None of the mutations were detected in the proband's sister.

CONCLUSIONS

The study proves that mutations of CTSC gene are responsible for the phenotype of Papillon-Lefèvre syndrome.
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[Papillon-Lefèvre syndrome: A new case]

Papillon-Lefèvre syndrome (PLS) is a rare primary immunodeficiency, which combines severe periodontal disease with edentulism and palmoplantar keratosis (PPK). PLS is inherited as an autosomal recessive trait and is due to mutations in the cathepsin C gene. The biological properties of the neutrophils (PN) are altered, leading to a gingival dysbiosis and bacterial overgrowth, with intense inflammation of the periodontium. We report the observation of a 4-year-old girl who presented to the clinic with gingivitis, partial edentulism, and PPK, whose diagnosis, raised after a long delay, was suggested by null cathepsin C activity and confirmed by the presence of heterozygous mutations in exon 4: c.628C>T, pArg210* and in exon 7: c.1286G>A, p.Trp429*. A multidisciplinary approach transformed the functional and esthetic prognosis and psychological behavior of this child. This classical observation describes this poorly known phenotype.

Analysis of urinary cathepsin C for diagnosing Papillon-Lefèvre syndrome

Papillon-Lefèvre syndrome (PLS) (OMIM: 245000) is a rare disease characterized by severe periodontitis and palmoplantar keratoderma. It is caused by mutations in both alleles of the cathepsin C (CatC) gene CTSC that completely abrogate the proteolytic activity of this cysteine proteinase. Most often, a genetic analysis to enable early and rapid diagnosis of PLS is unaffordable or unavailable. In this study, we tested the hypothesis that active CatC is constitutively excreted and can be easily traced in the urine of normal subjects. If this is true, determining its absence in the urine of patients would be an early, simple, reliable, low-cost and easy diagnostic technique. All 75 urine samples from healthy control subjects (aged 3 months to 80 years) contained proteolytically active CatC and its proform, as revealed by kinetic analysis and immunochemical detection. Of the urine samples of 31 patients with a PLS phenotype, 29 contained neither proteolytically active CatC nor the CatC antigen, so that the PLS diagnosis was confirmed. CatC was detected in the urine of the other two patients, and genetic analysis revealed no loss-of-function mutation in CTSC, indicating that they suffer from a PLS-like condition but not from PLS. Screening for the absence of urinary CatC activity soon after birth and early treatment before the onset of PLS manifestations will help to prevent aggressive periodontitis and loss of many teeth, and should considerably improve the quality of life of PLS patients.

A novel large deletion combined with a nonsense mutation in a Chinese child with Papillon-Lefèvre syndrome

BACKGROUND AND OBJECTIVE

Papillon-Lefèvre Syndrome (PLS) is a rare autosomal recessive hereditary disease (MIM245000). The syndrome is characterized by palmoplantar keratoderma and early onset periodontitis, caused by CTSC gene mutation. The mutation in CTSC previously reported is mainly point mutations. Large deletion in the CTSC gene has not yet been reported.

MATERIAL AND METHODS

We collected 5 mL peripheral blood from a patient with PLS and her family members and used the direct sequencing method to perform CTSC bidirectional sequencing. We also used FISH to analyze the approximate locations of the ends of the missing fragment and then determined the fragment sequence through direct sequencing.

RESULTS

The result demonstrated that the patient have a 110 kb deletion (Chr11: 88032292: 88142997(NC_000011)) combined with a nonsense mutation (Gln182Ter) in this gene.

CONCLUSION

Our study reveals a compound mutation consisting of a large deletion and a nonsense mutation, which provides a new insight in the mutation type of CTSC gene.