DERMATOLOGIC DISORDERS

Question 1

INCONTINENTIA PIGMENTI

Answer 1

Hair, skin, teeth, nails; Skin»infancy/birth with blistering rash»heals»wart-like skin growths»hyperpigmentation in swirl pattern&raquo_space; adulthood hypopigmentation; small or missing teeth, Genetics: X-linked dominant (65% de novo): Lethal in males; IKBKG gene Testing Strategy: Common 11.7 kb del in IKBKG

Question 2

ADAMS OLIVER SYN

Answer 2

Aplasia cutis congenita (ACC) of the scalp + Terminal transverse limb defects (TTLD) (lower extremities > affected than upper extremities), congenital cardiac malformations can be present; there are non-genetic reasons for ACC (birth trauma, amniotic bands, teratogens); Genetics: A dominant genes include NOTCH1, DLL4, RBPJ, ARRHGAP31, A recessive genes include DOCK6, EOGT, reduced penetrance; Testing strategy: Clinic dx available, NGS panel sensitivity about 50%

Question 3

HIDROTIC ECTODERMAL DYSPLASIA

Answer 3

“The hypos” hair, sweat, teeth&raquo_space; hypotrichosis, hypohidrosis, hypodontia; Mutlple modes of inheritance but X-linked most common; If suspect X-linked, NGS of EDA; Otherwise, NGS panel of EDAR, ADARADD, WNT10A; If X-linked, at risk females can undergo sweat test (mosaic distribution of sweat pores)

Question 4

ALBINISM/OCULOCUTANEOUS ALBINISM

Answer 4

Types 1-4

Question 5

EPIDERMOLYSIS BULLOSA

Answer 5

Skin fragility&raquo_space; blistering that heals w/ milia and scarring, Affects whole body including orally (can lead to severe dysphagia) and eyes (can lead to vision loss); “mitten” hands and feet, High risk for squamous cell carcinoma, dystrophic/absent nails; Genetics: Dystrophic EB caused by mutations in COL7A, can be A dominant or A recessive (most severe is biallelic mutations in COL7A)

Question 6

HEMANSKY-PUDLAK SYN

Answer 6

Oculocutaneous albinsim + prolonged/abnl bleeding (absent platelet delta granules) + pulmonary fibrosis; Genetics: All types A recessive–most common gene HSP1 gene; Founder mutations for Puerto Rican and Jewish ancestries