Oculocutaneous albinism type 1A

General Information (adopted from Orphanet):

Synonyms, Signs: ALBINISM I
OCULOCUTANEOUS ALBINISM, TYROSINASE-NEGATIVE
OCULOCUTANEOUS ALBINISM, TYPE I
OCA1A
ATN
OCA1
Tyrosinase-negative oculocutaneous albinism
Number of Symptoms 24
OrphanetNr: 79431
OMIM Id: 203100
ICD-10: E70.3
UMLs:
MeSH:
MedDRA:
Snomed:

Prevalence, inheritance and age of onset:

Prevalence: No data available.
Inheritance: Autosomal recessive
[Orphanet]
Age of onset: Neonatal
Infancy
[Orphanet]

Disease classification (adopted from Orphanet):

Parent Diseases: Oculocutaneous albinism type 1
 -Rare eye disease
 -Rare genetic disease
 -Rare skin disease

Symptom Information: Sort by abundance 

1
(HPO:0000486) Strabismus 1951438 IBIS 576 / 7739
2
(HPO:0001107) Ocular albinism Very frequent [Orphanet] 1951438 IBIS 40 / 7739
3
(HPO:0007750) Hypoplasia of the fovea 1951438 IBIS 11 / 7739
4
(HPO:0000649) Abnormality of visual evoked potentials Frequent [Orphanet] 6187545 IBIS 34 / 7739
5
(HPO:0000505) Visual impairment Frequent [Orphanet] 1951438 IBIS 297 / 7739
6
(HPO:0000639) Nystagmus Very frequent [Orphanet] 1951438 IBIS 555 / 7739
7
(HPO:0000613) Photophobia Very frequent [Orphanet] 19060277 IBIS 158 / 7739
8
(HPO:0008059) Aplasia/Hypoplasia of the macula Very frequent [Orphanet] 11860983 IBIS 21 / 7739
9
(HPO:0004349) Reduced bone mineral density Occasional [Orphanet] 165 / 7739
10
(HPO:0007587) Numerous pigmented freckles Frequent [Orphanet] 22 / 7739
11
(HPO:0001010) Hypopigmentation of the skin Very frequent [Orphanet] 115122 IBIS 46 / 7739
12
(HPO:0011364) White hair 13680365 IBIS 4 / 7739
13
(HPO:0200098) Absent skin pigmentation 115122 IBIS 2 / 7739
14
(HPO:0000962) Hyperkeratosis Occasional [Orphanet] 216 / 7739
15
(HPO:0008069) Neoplasm of the skin Occasional [Orphanet] 84 / 7739
16
(HPO:0005599) Hypopigmentation of hair Very frequent [Orphanet] 13680365 IBIS 38 / 7739
17
(OMIM) Translucent irides 13825323 IBIS 3 / 7739
18
(OMIM) Positive angle kappa (appearance of exotropia but no shift on cover test) 15059699 IBIS 2 / 7739
19
(HPO:0007370) Aplasia/Hypoplasia of the corpus callosum Occasional [Orphanet] 10332009 IBIS 180 / 7739
20
(OMIM) Absent tyrosinase activity 2120217 IBIS 1 / 7739
21
(OMIM) Albinotic optic disc 15059699 IBIS 1 / 7739
22
(HPO:0012795) Abnormality of the optic disc Frequent [Orphanet] 15059699 IBIS 187 / 7739
23
(OMIM) Absent retinal pigment 20301345 IBIS 1 / 7739
24
(OMIM) Misrouting of the optic nerves at the chiasm 20301345 IBIS 2 / 7739

Associated genes:

TYR;

ClinVar (via SNiPA)

Gene symbol Variation Clinical significance Reference

Additional Information:

Description: (OMIM) Oculocutaneous albinism is a genetically heterogeneous congenital disorder characterized by decreased or absent pigmentation in the hair, skin, and eyes. The term 'albinism' includes specific ocular changes that are the results of reduced amounts of melanin in the ...
Diagnosis OMIM King and Olds (1985) examined hairbulb tyrosinase activity in 72 individuals with albinism and 64 obligate heterozygotes. Several different types were distinguished based on biochemical features. Type IA was tyrosinase-negative and type IB had low or no measurable ...
Clinical Description OMIM Taylor (1978) pointed out that in the albino the ganglion cell layer does not thin out in the foveolar pit but shows a layer 6 to 8 cells thick where there should be none. He commented that 'this ...
Genotype-Phenotype Correlations OMIM Gronskov et al. (2009) analyzed 4 known OCA genes, TYR, OCA2, TYRP1, and MATP, in 62 patients with autosomal recessive albinism; they identified 2 mutations in 1 OCA gene in 44% of the patients. Mutations in TYR were ...
Molecular genetics OMIM In a child with tyrosinase-negative oculocutaneous albinism, Tomita et al. (1989) identified a homozygous 1-bp insertion in the TYR gene (606933.0001).

In a patient with classic tyrosinase-negative OCA, Spritz et al. (1989) found a thr-to-lys substitution ...

Population genetics OMIM Froggatt (1960) estimated a phenotype frequency of albinism I to be 1 in 10,000 in Northern Ireland. First-cousin marriages occurred in 4.5% of the parents. An excess of males was almost exclusively in the probands and the sex ...