Whole-exome sequencing in the clinical setting: Establishing a foothold for precision medicine in genodermatoses and other diseases

@#The concept of “precision medicine” has been a mainstay in discourses about the future of medicine, although it was not until the completion of the Human Genome Project that genetic associations to Mendelian diseases have risen dramatically. Since genetic variations in most (85%) monogenic or oligogenic diseases reside in exons, whole-exome sequencing (WES) serves as a pivotal tool in the identification of causative variants in genodermatoses and other diseases, leading to efficient and timely diagnosis. Here, we share our current diagnosis protocol for genodermatoses using WES as a first-tier solution. Two cases are presented to demonstrate the process of identifying germline variants and one case for a somatic variant. In the first case, a germline missense mutation in COL7A1 (exon73:c.G6127A) was identified for a patient that presented with clinical symptoms of dystrophic epidermolysis bullosa (DEB). Immunofluorescence study revealed decreased collagen VII expression in the dermal-epidermal junction. In case 2, we detected a germline missense mutation in KRT16 (exon1:c.374A>G) in a patient with palmoplantar keratoderma (PPK) and congenital pachyonychia. Sanger sequencing and segregation analysis confirmed the variant detected in WES. For case 3, a patient with linear nevus comedonicus was found to have a somatic missense mutation in NEK9 (exon4:c.500T>C), which was only detected in the lesional DNA sample. Thus, WES shows great potential as a diagnostic tool for monogenic or oligogenic genodermatoses. Since omics is a technology-driven tool, we expect that reaching precision medicine is ever closer.

Cutaneous protothecosis: A case report

Introduction@#Cutaneous protothecosis usually presents as pyoderma-like lesions or infiltrating papules and plaques on the extensor side of the extremities. It can be misdiagnosed as eczema, pyoderma, or a fungal infection. Although it has been isolated from a swimming pool, sewers and rivers in the Philippines, there has been no reported case of cutaneous protothecosis in the country.@*Case summary@#A 78-year-old Taiwanese male farmer visited the dermatology clinic due to a six-month history of a large, pruritic erythematous plaque studded with papulopustules on his left forearm. A potassium hydroxide (KOH) examination showed negative for hyphae or spores. And a skin biopsy showed morula-like bodies, which were highlighted by the Periodic acid-Schiff stain.@*Conclusion@#We report a case of cutaneous protothecosis from Taiwan so Filipino dermatologists will be aware of the clinical and histopathologic manifestations and management of cutaneous protothecosis.

The practical diagnostic approach for hereditary Epidermolysis Bullosa in the era of next generation sequencing

@#The new era of molecular diagnostics has provided new insights in both routine clinical work and research in hereditary epidermolysis bullosa (EB). Several different approaches and techniques have provided significant advantages in terms of diagnostic accuracy, predict- ing prognoses, clarifying the pathogenesis, and developing new therapies. In many developing countries, however, modern laboratory techniques remain inaccessible. Therefore, a practical diagnosticmatrix has been developed to predictthe diagnosis and subtype of EB. In thisreview,we highlight themolecular and practicaltechniquesin diagnosing hereditary EB.

Diffuse cutaneous systemic sclerosis: A case report

@#<p style="text-align: justify;"><strong>BACKGROUND: </strong>Systemic sclerosis (SSc) is a rare, connective tissue  disease  with  multisystem involvement.This is due to immunological processes,vascular endothelial cell injury  and extensive activation of fibrolast that commonly affects the skin and other internal organs such as the esophagus, lungs, heart, and kidneys. SSc has one of the highest mortality among  the  autoimmune  rheumatic  diseases,  hence  the  emphasis  on  the  early  recognition  and  management  to  prevent significant progression of the disease. <br /><strong>CASE:</strong> A 22-year-old  female  presented  with  a  one-year history of multiple hard and hypopigmented patches on the face, neck, trunk and upper extremities. Further examination revealed mask-like facies, microstomia, frenulum sclerosis, Raynaud's phenomenon, pitted scars on the digital pulp of hands  and  sclerodactyly.Baseline  blood  chemistry,chest radiograph and electrocardiography  were  all  negative  for systemic involvement. Autoantibodies were positive for dsDNA, SS-A/Ro and Scl-70. Skin biopsy revealed sclerosing dermatitis, which was consistent with SSc. <br /><strong>OUTCOME:</strong> The  patient  was  initially  started  with  oral prednisone 0.5 mg/kg/day and was increased to 0.75 mg/kg/day for eight weeks. Prednisone was slowly tapered to 5.0 mg/day and methotrexate 15.0 mg/week was included in  the  management for eight weeks which resulted in decreased joint pains, halted the progression of skin induration, decreased in pruritus and palmar edema. <br /><strong>CONCLUSION:</strong> The characteristic dermatological findings of SSc are not only important signs to dermatologists, but these serves as diagnostic clues for clinicians from other disciplines as well. In our case, the presence of the autoantibody Scl-70 indicated the potential risk of pulmonary fibrosis and pulmonary arterial hypertension that accounts with high mortality.Hence,physicians should be aware of the possible risk of organ damage,even when asymptomatic because there is a high risk of disease progression. The importance of early recognition and a multidisciplinary approach lead to the good outcome in this case.</p>

Diffuse cutaneous systemic sclerosis: A case report

BACKGROUND: Systemic sclerosis (SSc) is a rare, connective tissue  disease  with  multisystem involvement.This is due to immunological processes,vascular endothelial cell injury  and extensive activation of fibrolast that commonly affects the skin and other internal organs such as the esophagus, lungs, heart, and kidneys. SSc has one of the highest mortality among  the  autoimmune  rheumatic  diseases,  hence  the  emphasis  on  the  early  recognition  and  management  to  prevent significant progression of the disease. CASE: A 22-year-old  female  presented  with  a  one-year history of multiple hard and hypopigmented patches on the face, neck, trunk and upper extremities. Further examination revealed mask-like facies, microstomia, frenulum sclerosis, Raynaud's phenomenon, pitted scars on the digital pulp of hands  and  sclerodactyly.Baseline  blood  chemistry,chest radiograph and electrocardiography  were  all  negative  for systemic involvement. Autoantibodies were positive for dsDNA, SS-A/Ro and Scl-70. Skin biopsy revealed sclerosing dermatitis, which was consistent with SSc. OUTCOME: The  patient  was  initially  started  with  oral prednisone 0.5 mg/kg/day and was increased to 0.75 mg/kg/day for eight weeks. Prednisone was slowly tapered to 5.0 mg/day and methotrexate 15.0 mg/week was included in  the  management for eight weeks which resulted in decreased joint pains, halted the progression of skin induration, decreased in pruritus and palmar edema. CONCLUSION: The characteristic dermatological findings of SSc are not only important signs to dermatologists, but these serves as diagnostic clues for clinicians from other disciplines as well. In our case, the presence of the autoantibody Scl-70 indicated the potential risk of pulmonary fibrosis and pulmonary arterial hypertension that accounts with high mortality.Hence,physicians should be aware of the possible risk of organ damage,even when asymptomatic because there is a high risk of disease progression. The importance of early recognition and a multidisciplinary approach lead to the good outcome in this case.