Phenotype and genotype correlation of inherited epidermolysis bullosa in Indonesia

BACKGROUND

Inherited epidermolysis bullosa (EB) is a group of genodermatoses with considerable clinical and genetic heterogeneity. Clinical diagnosis of the EB subtypes is frequently imprecise and requires confirmation with genetic testing. There is still limited study using genetic testing to identify EB subtypes in Indonesia. This study aims to identify the pathogenic variants of inherited EB patients at the Department of Dermatology and Venereology, Universitas Padjadjaran-Dr Hasan Sadikin General Hospital in Bandung, West Java, Indonesia and to describe the correlation between the phenotype and genotype of our patients.

METHODS

Twelve patients clinically diagnosed with EB were included in this study. Genetic testing was performed in collaboration with KK Women's and Children's Hospital, Singapore.

RESULTS

Pathogenic variants were identified in the COL7A1 gene in seven patients, namely Dominant Dystrophic EB (DDEB) with mutation types c.5945G>T, c.6218G>A, Recessive Dystrophic EB (RDEB) c.2005C>T, c.6081dup, c.1268C>T, c.1784C>T which are all known mutations. Novel mutations were found in the COL7A1 gene in two patients namely DDEB c.6253G>T and RDEB c.6740C>T. Two EB Simplex (EBS) patients showed mutation KRT14 gene as c.356T>C, c.373C>T which are known mutation. In addition, a novel mutation in LAMA3 gene c.2649del was found in one Junctional EB (JEB) patient.

CONCLUSION

The molecular diagnoses of 12 Indonesian EB patients were identified, of which three were novel pathogenic variants. Concordance between the initial clinical diagnosis and genetic testing was only 33%. This demonstrated the importance of early genetic testing for accurate diagnosis, prognostication, management and genetic counselling.

A novel NSDHL variant in CHILD syndrome with gastrointestinal manifestations and localized skin involvement

Background

CHILD syndrome is an X‐linked dominant disorder associated with pathogenic mutations in the NSDHL gene. The condition is predominantly found in females as it is lethal in males. Most cases present at birth with extensive unilateral ichthyosiform erythroderma involving the trunk and limbs. Milder and less extensive presentations have been reported, leading to misdiagnosis especially during early childhood.

Methods and Results

We report an adult female of Malay ancestry who presented with minimal skin and limb involvement. She was only diagnosed in adulthood when she presented with gastrointestinal symptoms and worsening of skin manifestations. The clinical diagnosis was suspected after a combination of clinical, pathological and immunohistochemistry correlation, and molecularly confirmed with the discovery of a frameshift variant in NSDHL. The novel variant was inherited from her mother who had some linear hypopigmented patches over the medial aspects of both her arms and right forearm.

Conclusion

We uncovered a novel frameshift variant associated with presentations that cast a new light on the clinical features of CHILD syndrome.

CARD14-associated papulosquamous eruption (CAPE) in a toddler responding to treatment with acitretin

CARD14-associated papulosquamous eruption (CAPE) is a rare autosomal dominant dermatosis that presents classically in early childhood with clinical features of both psoriasis and pityriasis rubra pilaris (PRP). The disease is known to be refractory to topical and systemic therapies classically used for psoriasis, with the majority of reported cases requiring treatment with biologics, such as ustekinumab and secukinumab. We present a toddler with a clinical presentation consistent with CAPE and found to have a novel heterozygous variant of the CARD14 gene. She was refractory to treatment with topical emollients and topical corticosteroids, but responsive to oral acitretin.

Palmoplantar keratoderma, oral involvement, and homozygous CTSC mutation in two brothers from Cambodia

Haim-Munk syndrome (HMS) and Papillon-Lefevre syndrome (PLS) are phenotypic variants of palmoplantar keratoderma (PPK) with progressive early-onset periodontitis and dental caries. HMS and PLS have been associated with homozygous or compound heterozygous mutations in the lysosomal protease gene Cathepsin C (CTSC). There have been only a few documented cases of CTSC mutations in patients from South-East Asia. We report the clinical findings of two Cambodian brothers who presented with diffuse, demarcated PPK with transgrediens extending to the elbows and knees, as well as pachyonychia and dental caries. Arachnodactyly and periodontitis were also found in the older brother. Next-generation sequencing unveiled a homozygous missense variant in CTSC (NM_001814.5: c.1337AC: p.(Asp446Ala)) in both brothers. Both parents were heterozygous for the variant, while an unaffected older brother was homozygous for the wild-type allele. Our study adds to the spectrum of mutations and associated clinical presentations for this rare genodermatosis.