Genetic Skin Conditions

Question 1

What is tuberous sclerosis?

Answer 1

Autosomal dominant inherited

Causes the development of hamartomas

Question 2

Mutations in tuberous sclerosis

Answer 2

TSC1 = codes for hamartin, chromosome 9
or
TSC2 = codes for tuberin, chromosome 16

Question 3

Common hamartoma sites in tuberous sclerosis

Answer 3

Skin
Brain
Lungs
Heart
Kidneys
Eyes

Question 4

Presentation of tuberous sclerosis

Answer 4

Ash leaf macule
Facial angiofibromas
Poliosis (white patch of hair)
Shagreen patches (thickened, dimples, pigmented patches of skin)
Café-au-lait spots
Periungual fibromata and longitudinal ridging
Enamel pitting

Question 5

Neurological features of tuberous sclerosis

Answer 5

Epilepsy

Learning disability and developmental delay

Question 6

What is the use of Wood’s lamp in tuberous sclerosis?

Answer 6

Makes ash leaf macules more obvious

Question 7

Treatment of tuberous sclerosis

Answer 7

Symptomatic treatment

Question 8

What is oculocutaneous albinism?

Answer 8

Autosomal dominant inheritance

Congenital absence of melanin due to absent or defective tyrosinase (which catalyses the production of melanin)

Question 9

Presentation of oculocutaneous albinism

Answer 9

Sun sensitivity

Visual problems: lack of pigment in the retina, photophobia, nystagmus, amblyobia (lazy eye)

Question 10

Complication of oculocutaneous albinism and xeroderma pigmentosum

Answer 10

Skin cancer

Question 11

What is xeroderma pigmentosum?

Answer 11

Autosomal recessive inheritance

Cellular hypersensitivity to ultraviolet (UV) radiation, as a result of a defect in the DNA repair system

Question 12

Presentation of xeroderma pigmentosum

Answer 12

Photosensitivity
Photodamage
Acute sunburn reaction on minimal UV exposure with diffuse and prolonged erythema
Neurological degeneration
Dryness
Solar lentigines
Atrophy and telangiectasia
Actinic keratoses