Learn and talk about Oculocutaneous albinism, Albinism, Amino acid metabolism disorders, Autosomal recessive disorders

Oculocutaneous albinism
Classification and external resources
ICD-10	E 70.3
ICD-9	270.2
MeSH	D016115

Oculocutaneous albinism is a form of albinism involving the eyes ("oculo-"), skin ("-cutaneous"), and according to some definitions, the hair as well.^[1]

Four types of oculocutaneous albinism have been described, all caused by a disruption of melanin synthesis and all autosomal recessive disorders.^[2]^[3]^:864

1 Types
2 See also
3 External links
4 References

Types[edit]

Name	OMIM	Gene	Description
OCA1	203100	TYR	OCA1 is caused by an alteration of the tyrosinase gene, and can occur in two variations. The first is OCA1a, and means that the organism cannot develop pigment at all. The hair is usually white (often translucent) and the skin very pale. Vision usually ranges from 20/200 to 20/400. The second is OCA1b, which has several subtypes itself. Some individuals with OCA1b can tan and also develop pigment in the hair.^[4]^{[verification needed]} One subtype of OCA1b is called OCA1b TS (temperature sensitive), where the tyrosinase can only function below a certain temperature, which causes the body hair in cooler body regions to develop pigment (i.e. get darker). (An equivalent mutation produces the coat pattern in Siamese cats.^[5]) Another variant of OCA1b, called Albinism, yellow mutant type (OMIM: 606952) is more common among the Amish than in other populations, and results in blonde hair and the eventual development of skin pigmentation during infancy, though at birth is difficult to distinguish from other types.^[6]^[7] About 1 in 40,000 people have some form of OCA1.^[6]^[8]
OCA2	203200	OCA2	The most common type of albinism, is caused by mutation of the P gene. People with OCA2 generally have more pigment and better vision than those with OCA1, but cannot tan like some with OCA1b. A little pigment can develop in freckles or moles.^[4] People with OCA2 usually have fair skin but often not as pale as OCA1, and pale blonde to golden, reddish-blonde, or even brown hair, and most commonly blue eyes. Affected people of African descent usually have a different phenotype (appearance): yellow hair, pale skin, and blue, gray or hazel eyes. About 1 in 15,000 people have OCA2.^[6]^[8] The gene MC1R doesn't cause OCA2, but does affect its presentation.^[1]
OCA3	203290	TYRP1	Has only been partially researched and documented. It is caused by mutation of the tyrosinase-related protein-1 (Tyrp1) gene. Cases have been reported in Africa and New Guinea. Affected individuals typically have red hair, reddish-brown skin and blue or gray eyes. Variants may include rufous oculocutaneous albinism (ROCA or xanthism) (OMIM: 278400). The incidence rate of OCA3 is unknown.^[6]^[8]
OCA4	606574	SLC45A2	Is very rare outside of Japan, where OCA4 accounts for 24% of albinism cases. OCA4 can only be distinguished from OCA2 through genetic testing, and is caused by mutation of the membrane-associated transporter protein (MATP) gene.^[6]^[8] Several German patients were identified in 2004.^[9]

External links[edit]

References[edit]

^ ^a ^b "Oculocutaneous albinism - Genetics Home Reference".
^ Grønskov K, Ek J, Brondum-Nielsen K (2007). "Oculocutaneous albinism". Orphanet Journal of Rare Diseases 2: 43. doi:10.1186/1750-1172-2-43. PMC 2211462. PMID 17980020.
^ James, William; Berger, Timothy; Elston, Dirk (2005). Andrews' Diseases of the Skin: Clinical Dermatology. (10th ed.). Saunders. ISBN 0-7216-2921-0.
^ ^a ^b "Facts about Albinism", by Dr. Richard King et al.
^ Giebel LB, Tripathi RK, King RA, Spritz RA (March 1991). "A tyrosinase gene missense mutation in temperature-sensitive type I oculocutaneous albinism. A human homologue to the Siamese cat and the Himalayan mouse". The Journal of Clinical Investigation 87 (3): 1119–22. doi:10.1172/JCI115075. PMC 329910. PMID 1900309.
^ ^a ^b ^c ^d ^e Online Mendelian Inheritance in Man Database, at Johns Hopkins University (see also Mendelian Inheritance in Man for more information about this source).
^ "Ocular Manifestations of Albinism", by Dr. Mohammed O. Peracha, at eMedicine, 13 September 2005; retrieved 31 March 2007
^ ^a ^b ^c ^d "Albinism", by Dr. Raymond E. Boissy, Dr. James J. Nordlund, et al., at eMedicine, 22 August 2005; retrieved 31 March 2007
^ Rundshagen U, Zühlke C, Opitz S, Schwinger E, Käsmann-Kellner B (February 2004). "Mutations in the MATP gene in five German patients affected by oculocutaneous albinism type 4". Human Mutation 23 (2): 106–10. doi:10.1002/humu.10311. PMID 14722913.

Inborn error of amino acid metabolism (E70–E72, 270)

K→acetyl-CoA

Lysine/straight chain	Glutaric acidemia type 1 type 2 Hyperlysinemia Pipecolic acidemia Saccharopinuria

Leucine	Maple syrup urine disease Isovaleric acidemia 3-Methylcrotonyl-CoA carboxylase deficiency 3-hydroxy-3-methylglutaryl-CoA lyase deficiency 3-Methylglutaconic aciduria 1

Tryptophan	Hypertryptophanemia

G→pyruvate→citrate

Glycine	Sarcosinemia D-Glyceric acidemia Glutathione synthetase deficiency Glycine→Creatine: GAMT deficiency Glycine encephalopathy

G→glutamate→
α-ketoglutarate

Histidine	Carnosinemia Histidinemia Urocanic aciduria

Proline	Hyperprolinemia Prolidase deficiency

Glutamate/glutamine	SSADHD

G→propionyl-CoA→
succinyl-CoA

Valine	Maple syrup urine disease Hypervalinemia Isobutyryl-CoA dehydrogenase deficiency

Isoleucine	Maple syrup urine disease Beta-ketothiolase deficiency 2-Methylbutyryl-CoA dehydrogenase deficiency

Methionine	Hypermethioninemia Homocystinuria Cystathioninuria

General BC/OA	Propionic acidemia Methylmalonic acidemia Methylmalonyl-CoA mutase deficiency

G→fumarate

Phenylalanine/tyrosine

Phenylketonuria	Tetrahydrobiopterin deficiency 6-Pyruvoyltetrahydropterin synthase deficiency

Tyrosinemia	Type II tyrosinemia Type III tyrosinemia/Hawkinsinuria Alkaptonuria/Ochronosis Type I tyrosinemia

Tyrosine→Melanin	Albinism: Ocular albinism (1) Oculocutaneous albinism (Hermansky–Pudlak syndrome) Waardenburg syndrome

Tyrosine→Norepinephrine	Dopamine beta hydroxylase deficiency reverse: Brunner syndrome

G→oxaloacetate

Urea cycle/Hyperammonemia (arginine aspartate)	N-Acetylglutamate synthase deficiency Carbamoyl phosphate synthetase I deficiency Ornithine transcarbamylase deficiency/translocase deficiency Citrullinemia Argininosuccinic aciduria Argininemia

Transport/
IE of RTT

Other

M: MET

mt, k, c/g/r/p/y/i, f/h/s/l/o/e, a/u, n, m

k, cgrp/y/i, f/h/s/l/o/e, au, n, m, epon

m (A16/C10), i (k, c/g/r/p/y/i, f/h/s/o/e, a/u, n, m)

Pigmentation disorders/Dyschromia (L80–L81, 709.0)

Hypo-/
leucism

Loss of melanocytes	vitiligo: Quadrichrome vitiligo · Vitiligo ponctué · syndromic (Alezzandrini syndrome · Vogt–Koyanagi–Harada syndrome) melanocyte development: Piebaldism · Waardenburg syndrome · Tietz syndrome

Loss of melanin/ amelanism	albinism: Oculocutaneous albinism · Ocular albinism melanosome transfer: Hermansky–Pudlak syndrome · Chédiak–Higashi syndrome · Griscelli syndrome (Elejalde syndrome · Griscelli syndrome type 2 · Griscelli syndrome type 3) other: Cross syndrome · ABCD syndrome · Albinism–deafness syndrome · Idiopathic guttate hypomelanosis · Phylloid hypomelanosis · Progressive macular hypomelanosis

Leukoderma w/o hypomelanosis	Vasospastic macule · Woronoff's ring · Nevus anemicus

Ungrouped	ungrouped: Nevus depigmentosus · Postinflammatory hypopigmentation · Pityriasis alba · Vagabond's leukomelanoderma · Yemenite deaf-blind hypopigmentation syndrome · Wende–Bauckus syndrome

Hyper-

Melanin/
Melanosis/
Melanism

Reticulated	Dermatopathia pigmentosa reticularis · Pigmentatio reticularis faciei et colli · Reticulate acropigmentation of Kitamura · Reticular pigmented anomaly of the flexures · Naegeli–Franceschetti–Jadassohn syndrome · Dyskeratosis congenita · X-linked reticulate pigmentary disorder · Galli–Galli disease · Revesz syndrome

Diffuse/ circumscribed	Lentigo/Lentiginosis: Lentigo simplex · Liver spot · Centrofacial lentiginosis · Generalized lentiginosis · Inherited patterned lentiginosis in black persons · Ink spot lentigo · Lentigo maligna · Mucosal lentigines · Partial unilateral lentiginosis · PUVA lentigines Melasma · Erythema dyschromicum perstans · Lichen planus pigmentosus · Café au lait spot · Poikiloderma (Poikiloderma of Civatte · Poikiloderma vasculare atrophicans) · Riehl melanosis

Linear	Incontinentia pigmenti · Scratch dermatitis · Shiitake mushroom dermatitis

Other/ungrouped	Acanthosis nigricans (Acral acanthotic anomaly) · Freckle · Familial progressive hyperpigmentation · Pallister–Killian syndrome · Periorbital hyperpigmentation · Photoleukomelanodermatitis of Kobori · Postinflammatory hyperpigmentation · Transient neonatal pustular melanosis

Other
pigments

iron: Hemochromatosis · Iron metallic discoloration · Pigmented purpuric dermatosis (Schamberg disease, Majocchi's disease, Gougerot–Blum syndrome, Doucas and Kapetanakis pigmented purpura/Eczematid-like purpura of Doucas and Kapetanakis, Lichen aureus, Angioma serpiginosum) · Hemosiderin hyperpigmentation

other metals: Argyria · Chrysiasis · Arsenic poisoning · Lead poisoning · Titanium metallic discoloration

other: Carotenosis · Tattoo · Tar melanosis

Dyschromatoses

Dyschromatosis symmetrica hereditaria · Dyschromatosis universalis hereditaria

M: INT, SF, LCT

anat/phys/devp

noco (i/b/d/q/u/r/p/m/k/v/f)/cong/tumr (n/e/d), sysi/epon

proc, drug (D2/3/4/5/8/11)

Original courtesy of Wikipedia: http://en.wikipedia.org/wiki/Oculocutaneous_albinism — Please support Wikipedia.
A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia.

Oculocutaneous albinism

Contents

Types[edit]

See also[edit]

External links[edit]

References[edit]

Talk About Oculocutaneous albinism

Support Wikipedia