pigmentary disorders Flashcards
oculocutaneous albinism
OCA1a - no pigment skin/hair OCA1b - no pigment skin/hair, but time & low temperature may lead to pigment development in some areas OCA2 - light brown hair, most common*** OCA3 - red hair OCA4 - seen in Japanese, like OCA2
OCA1a/b —> TYR
OCA2 –> OCA2, may be seen in Angelman or Prader Willi, MOST COMMON
OCA3 —> TYRP1
OCA4 –> SLC45A2
silvery hair syndrome
chediak-higashi, elejalde syndrome, and griscelli.
All of these are ARecessive
griscelli
GS1 - neurologic impairment, MYO5A
GS2 - immunodeficiency, RAB27A
GS3 - skin only, MLPH
chediak-higashi
defect in LYST gene
multisystem disorder including skin + blood diathesis + silvery hair + oculocutaneous albinism + neuro defect
death typically occurs by age 10
elejalde syndrome
similar to GS1
Hermansky-Pudlak syndrome
Autosomal Recessive (AR)
a/w HPS1 gene and more
oculocutaneous albinism + bleeding diathesis + buildup of ceroid lipofuscin
more common in puerto ricans (#1 cause of death: pulmonary fibrosis)
p/w ecchymoses, nosebleeds, menorrhagia, photophobia
complications –> gran colitis, pulm fibrosis, cardiomyopathy, and renal failure
Piebaldism
AD
defect in c-KIT gene
presents with white forelock (poliosis), leukoderma, no internal issues
Waardenburg syndrome
AD
presents with white forelock (poliosis) + internal issues
W1 white forelock, dystopia canthorum, heterochromia irides, deafness
W2 deafness
W3 upper limb abnormality
W4 hirschprung disease
McCune Albright syndrome
NON-INHERITED somatic mutation in GNAS1 gene
p/w triad: cafe au lait macules + polyostotic fibrous dysplasia + endocrine dysfunction (e.g. hypophosphatemic rickets, precocious puberty, infantile Cushing syndrome)
reticulate acropigmentation of kitamura
ADominant
ADAM10 gene defect
p/w reticulated pattern on the dorsal hands/feet
Dowling degos disease
ADominant keratin 5 gene defect p/w reticulated hyperpigmentation of the axillae, groin, trunk a/w EBS with mottled pigmentation Subtype - galli-galli disease
lentiginoses syndromes
LEOPARD syndrome carney complex (NAME, LAMB) peutz-jeghers syndrome laugier-hunziker syndrome Cronkhite-canada syndrome centrofacial lentiginosis bannayan-riley ruvalcaba
dyschromatosis symmetrica hereditaria
ADominant
ADAR (SRAD) gene defect
p/w dyschromia on face and/or extremities
seen in Japanese/chinese patients, often by age 6
dyschromatosis universalis hereditaria
ADominant
ABCB6 gene defect
p/w generalized dyschromia, pterygium
may be a/w short stature, idiopathic torsion dystonia, x linked ocular albinism, photosensitivity, neurosensory hearing loss
dyskeratosis congenita
AD, AR, XLR
TERT(AR), TERC (AD), DKC1 (XLR)
p/w bone marrow failure, skin dyschromia, oral leukoplakia, and onychodystrophy
cause of death: bone marrow failure, pulmonary fibrosis, malignancy
Average age of death: 16 yo
naegeli-franceschetti-jadassohn syndrome NFJS
TRANSIENT dyschromia + dental issues (e.g. early loss of teeth)
dermatopathia pigmentosa reticularis DPR
PERSISTENT dyschromia + alopecia.
Epidermal Bullosa
further classified as simplex (epidermal), junctional (BMZ), dystrophic (lamina densa), and kindler (mixed levels)
Simplex -> localized, generalized severe, generalized intermediate, muscular dystrophy (AR), mottled pigmentation. All others are AD
Gene: keratin 5/14, plectin** for muscular dystrophy
Junctional -> generalized severe, generalized intermediate, pyloric atresia. All are AR
Gene: Laminin
*JEB severe - hoarse cry at birth, death within first few years from pulmonary failure OR sepsis
Dystrophic -> dominant (DDER, AD), recessive generalized intermediate(RDEB, AR), recessive generalized severe (RDEB, AR). Gene: COL7A1
*RDEB generalized severe - mitten deformities, limb contractures, SCC is #1 cause of death
Kindler -> skin fragility, photosensitivity, poikiloderma (AR)
Gene: FERMT1
lentiginosis syndromes
LEOPARD syndrome carney complex (NAME, LAMB) peutz-jeghers syndrome laugier-hunziker syndrome Cronkhite-canada syndrome centrofacial lentiginosis bannayan-riley ruvalcaba
LEOPARD syndrome
AD
PTPN11/SHP2 gene defect
lentigines, EKG, ocular hypertelorism, pulmonary stenosis, abnormal genital, growth retardation, deafness
carney complex (NAME, LAMB)
NAME - nevi, atrial myxoma, ephelides
LAMB - lentigo, atrial myxoma, blue rubber nevus
AD
PRKAR1A gene defect
peutz-jeghers syndrome
AD
STK11/LBK1 gene defect
pigmented spots on lips + GI polyps (a/w GI cancers)
laugier-hunziker syndrome
pigmented spots on lips, genitalia
Cronkhite-canada syndrome
lentigines of hands/feet, buccal mucosa
nail dystrophy
alopecia
intestinal polyps
centrofacial lentiginosis
lentigines on nose and cheeks sacral hypertrichosis developmental delay seizures dwarfism endocrine dysfunction
bannayan-riley ruvalcaba
PTEN defect
penile lentigines, lipoma, macrocephaly, developmental delay
