Genodermatoses - Photogenoderm

Question 1

Xeroderma pigmentosum presents with abnormal skin at birth

Answer 1

False - normal skin

Question 2

Xeroderma pigmentosum features in childhood - list in order of appearance

Answer 2

PAT DAM narrow nares
Pigmented macules
Achromic macules
Telangiectasias

Dry, scaly, atrophic skin , narrowed mouth and nares
AK’s, KA’s, 1000 x risk of BCC, SCC, MM

Question 3

Photo testing for XP should be in the 290-340nm spectrum

Answer 3

True

Question 4

Practically all patients with XP have solar lentigines by age of 1 year

Answer 4

False 2 years

Question 5

Ocular features of XP

Answer 5

Conjunctivitis
Photophobia
Pigmentation of lid and conjunctiva
Ectropion
Corneal vascularisation
Opacification
benign lid papilloma
BCC
MM

Question 6

Neurological features are more prevalent in the XP-V group

Answer 6

False XP-D

Question 7

List neurological features of XP

Answer 7

Progressive neurologic degeneration in 20-30%
Sensorineural deafness
Spasticity
Hyporeflexia
Ataxia

Question 8

Desanctis-Cacchione syndrome is a severe neurological disorder associated with XP and which features?

Answer 8

Microcephaly
Progressive decline in intellect
Spasticity
Hyporeflexia
Ataxia
Delayed growth and sexual development

Question 9

Potential tx for XP

Answer 9

—> BJD Aug 2019
—> topical enzyme liposomes of bacterial T4 endonuclease V or gene t/f to alleviate DNA repair defect
—> antibiotics - gentamicin allows for stop codon read-through
—> Coenzyme Q target oxidative stress
—> Isotretinoin , topical imiquimod, IL IFNa, oral vismodegib, pembrolizumab, nicotinamide

Question 10

Cockayne syndrome

Answer 10

Mickey Mouse in the loud club dealing cockayne, gets microcephaly , optic atrophy, cachexia but no skin cancers (he is black)

Mickey Mouse ears
deafness 
Clubbing
microcephaly
Optic atrophy
Cachexia
No skin cancers

Question 11

Cockayne syndrome inheritance

Answer 11

Autosomal recessive

ERCC6, ERCC8

Question 12

Trichothiodystrophy features

Answer 12

PIBIDS 
Photosensitivity
Ichthyosis 
Brittle hair
Infertility
Developmental delay 
Short stature 

Other features:
STANDBIC
Spasticity
Tremors
Ataxia
Nail dystrophy
Dental caries
Bony Defects
Immunodeficiency 
Cataracts

Question 13

Bloom syndrome inheritance

Answer 13

Autosomal recessive, RECQL3

Question 14

Bloom syndrome features

Answer 14

Late CALM bloomers with cheilitis, cancer and failure to thrive

• presents in first few months of life
• Cafe au lait macules
• IgA and M deficient
• long narrow faces, malar hypoplasia, prominent nose, small mandible

Cheilitis - blisters on lip common
FTT - hypogonadism , infertility, high pitched voice
Malignancies - GI adenocarcinoma, acute leukaemia, lymphoma

Question 15

What malignancies are associated with Bloom syndrome

Answer 15

GI adenocarcinoma
Lymphoma
Leukaemia
Skin cancers

Question 16

Which skin cancers are common with Cockayne syndrome

Answer 16

None

Question 17

Rothmund Thompson inheritance

Answer 17

autosomal recessive

RECQL4

Question 18

Rothmund Thompson features

Answer 18

short bald Roth gets sunburnt, can’t eat (dystrophic teeth) can’t use thumbs (hypoplastic), can’t smell (saddle nose) or pee (hypogonadism) or see (cataracts). Dies of osteosarcoma and skin cancers

ROTHMUND
Really short stature
Oral - dystrophic teeth and ocular cataracts
Tumours - osteosarcoma, fibrosarcoma, SCC
Hair - alopecia eyebrows/eyelashes, scalp
MSK - syndactyly, absent or hypoplastic thumbs
Urogenital - hypogonadism
Neuro - delayed, saddle nose
Derm - photosensitivity, cancers