Leber: congenital amaurosis (LCA)
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Degenerative disease of the retina. Autosomal recessive transmission but some cases of autosomal dominant transmission have been described.
From a genotypic point of view, 19 subtypes of LCA (acronym for Leber’s Congenital Amaurosis) have been described so far:
- LCA1: mutation of the GUCY2D gene (17p31.1) [MIM 204 000]
- LCA2: mutation of the RPE65 gene (1p31) [MIM 204 100]
- LCA3: mutation of the SPATA7 gene (14q31) [MIM 604 232]
- LCA4: mutation of the AIPL1 gene (17p13) [MIM 604 393]
- LCA5: mutation of the LCA5 gene (6q14) [MIM 604 535]
- LCA6: mutation of the RPGRIP1 gene (14q11) [MIM 613 826]
- LCA7: mutation of the CRX gene (19q13) [MIM 613 829]
- LCA8: mutation of the CRB1 gene (1q31) [MIM 613 835]
- LCA9: mutation of the NMNAT1 gene (1q36) [MIM 608 553]
- LCA10: mutation of the CEP290 gene (12q21) [MIM 611 755]: responsible of 21 % of the cases (Joubert's syndrome)
- LCA11: mutation of the IMPDH1 gene (7q32) [MIM 613 837]
- LCA12: mutation of the RD3 gene (1q32) [MIM 610 612]
- LCA13: mutation of the RDH12 gene (14q24) [MIM 612 712]
- LCA14: mutation of the LRAT gene (4q32) [MIM 613 341]
- LCA15: mutation of the TULP1 gene (6p21) [MIM 613 843]
- LCA16: mutation of the KCNJ13 gene (2q37) [MIM 614 186]
- LCA17: mutation of the GDF6 gene (8q22) [MIM 615 360]
- LCA18: mutation of the PRPH2 gene (6p21) [MIM 608 133]
- LCA19: mutation of the USP45 gene (6q16) [MIM 618 513]
The decrease of vision is usually obvious during the neonatal period or early childhood: dilated pupils reacting slowly to light, nystagmus, photophobia.
There are 3 categories of ophtalmologic anomalies:
(1) retinal aplasia due to an abnormality of the photoreceptors
(2) early degeneration of the photoreceptors
(3) photoreceptor dysfunction with a normal retinal anatomy.
At ophthalmoscopy: progressive appearance of a picture of retinitis pigmentosa.
The onset is usually isolated but may be associated with epilepsy or psychomotor retardation. Amaurosis can also be part of a syndrome as Joubert's syndrome (see this term).
Anesthetic implications:
Visual impairment, photophobia. Sometimes epilepsy.
References:
Updated: March 2020