Genodermatoses & Nutritional Disorders MCQs

Ans. is 'd' i.e., Essential fatty acid In vitamin 'A' deficiency there is toad like skin also known as phrynoderma. o But this is due to associated deficiency of essential fatty acids.

There are two types of EB Acquired and Congenital The congenital has 3 types (Simple x, Junctional and Dystrophic) Keratin 14 : EB Simplex Laminin 4, Alpha 6 integrin : Junctional EB Collagen type 7: Dystrophic EB Reference: Rooks textbook of Dermatology, 9 th Edition Chapter 71, page 2

Hailey-Hailey Disease Synonym: Benign familial pemphigus Autosomal dominant inheritance ATP2Cl enzyme insufficiency Flexural distribution: Painful erosions, vesico-pustules and scaly erythematous plaques appear at sites of friction such as the sides of the neck, the axillae, the groins and the perineum. Reference: Rooks textbook of Dermatology, 9 th Edition, Chapter 66, page 10

Epidermolysis bullosa is a group of mechanobullous disorders in which the skin breaks down and blister forms due to minor trauma. It is a genetic disorder with mutations in skin proteins. Reference: Rooks textbook of Dermatology, 9 th Edition Chapter 71, Page 2

Diseases characterized under the general term epidermolysis bullosa are a heterogeneous group of hereditary blistering disorders. All of them are characterized by induction of blisters by trauma and exacerbation of blistering in warm weather. Disorders can be categorized in 3 main headings, viz. epidermolysis bullosa simplex, junctional epidermolysis bullosa and dystrophic epidermolysis bullosa. Affected infant is usually blistered at birth or develops lesions during the neonatal period. Reference: Rooks textbook of Dermatology, 9 th Edition Chapter 71, page 11

DIF is positive only in the immunobullous group of disorders due to presence of auto-antibody-antigen complexes in the skin. So, it will be positive in EB acquisita as it is a subepidermal IB disorder DIF will be negative in diseases which have a genetic etiology like Congenital EB, hailey hailey disease, darriers disease and Transient acantholytic dermatoses (Grovers disease). Reference: Rooks textbook of Dermatology, 9 th Edition, Chapter 66, Page 1

Explanation: Epidermolysis bullosa (EB) has acquired and congenital Among congenital types: Simplex, Junctional, and Dystrophic, each is linked to a specific structural protein defect: EB Simplex: Mutation is seen in Keratin 14 Junctional EB: Mutations happen in Laminin 4 and α6 integrin Dystrophic EB: Caused by mutations in Collagen type VII , the main component of anchoring fibrils Collagen VII defect is characteristic of dystrophic EB .

Neurofibromatosis type 1 (NF-1) or Von Recklinghausen disease is an autosomal dominant disorder. It is the most common hamartoma neoplastic syndrome The gene for NF-1 is located on chromosome 17 and encodes a gene product called neurofibromin Neurofibromin, a GTPase-activating protein, normally inhibits the rat sarcoma (RAS) pathway. Mutations of the NF-1 gene result in a lack of expression of neurofibromin, thereby promoting tumorigenesis. Reference: Rooks textbook of Dermatology, 9 th edition, Chapter 80, page 1