Retinal disorders
Gene: SLC38A8
Biallelic variants in SLC38A8 cause isolated foveal hypoplasia, chisamal misrouting in the absence of pigmentation defects. The variable phenotype being anterior segment dysgenesis (Poulter et al., 2013). Bare in mind chiasmal misrouting is not always reported due to lack of access to the visual evoked potentials (VEP) test, technical difficulty in performing the test on infants and inconsistent results during childhood (Campbell et al., 2019). The differential feature of SLC38A8 is the absence of pigmentation defects however assessing pigmentation status proves challenging especially in fair populations thus some genuine SLC38A8 cases are misdiagnosed as albinism (Campbell et al., 2019). Oculomotor defects such as nystagmus accompanies foveal hypoplasia in its syndromic and isolated forms.Created: 7 Mar 2022, 6:49 p.m. | Last Modified: 7 Mar 2022, 6:49 p.m.
Panel Version: 2.242
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
foveal hypoplasia, chiasmal misrouting, anterior segment dysgenesis; nystagmus
Publications
Green review from Mohammed Derar on green gene so no change in rating needed. Phenotypes updated.Created: 25 May 2022, 1:18 p.m. | Last Modified: 25 May 2022, 1:18 p.m.
Panel Version: 2.272
PMID: 32744312 Kuht et al 2020 - used a custom-targeted next generation sequencing gene panel was used to identify SLC38A8 mutations from a cohort of 511 nystagmus patients. They report 16 novel SLC38A8 mutations in 11 subjects from nine families. 2 families had homozygous variants, the other 7 had compound het variants. There was a mixture of missense, splice variants and nonsense variants. 90% of cases were initially misdiagnosed, prior to NGS, as PAX6-related phenotype or ocular albinism. All patients had severe grades of arrested retinal development with lack of a foveal pit and no cone photoreceptor outer segment lengthening.Created: 2 Dec 2020, 3:21 p.m. | Last Modified: 2 Dec 2020, 3:21 p.m.
Panel Version: 2.21
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Foveal hypoplasia 2, with or without optic nerve misrouting and/or anterior segment dysgenesis OMIM:609218; foveal hypoplasia - optic nerve decussation defect - anterior segment dysgenesis syndrome MONDO:0012216
Publications
Comment on list classification: Updated rating from Grey to Green after review and advice from Chris Campbell: Gene was added and rated Green by Mervyn Thomas. >3 unrelated cases of SLC38A8 variants causing foveal hypoplasia (MIM:609218) which is relevant phenotype for panel.Created: 21 Sep 2017, 7:54 a.m.
Comment on mode of inheritance: Biallelic mode of inheritance supported by OMIM.Created: 21 Sep 2017, 7:52 a.m.
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Foveal hypoplasia 2 with optic nerve misrouting with or without anterior segment dysgenesis
Publications
Variants in this GENE are reported as part of current diagnostic practice
Associated with foveal hypoplasia. OMIM #609218Created: 28 Nov 2016, 8:50 p.m.
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Foveal hypoplasia 2, with or without optic nerve misrouting and/or anterior segment dysgenesis
Publications
Phenotypes for gene: SLC38A8 were changed from Foveal hypoplasia 2, with or without optic nerve misrouting and/or anterior segment dysgenesis OMIM:609218; foveal hypoplasia - optic nerve decussation defect - anterior segment dysgenesis syndrome MONDO:0012216 to Foveal hypoplasia 2, with or without optic nerve misrouting and/or anterior segment dysgenesis OMIM:609218; foveal hypoplasia - optic nerve decussation defect - anterior segment dysgenesis syndrome MONDO:0012216; chiasmal misrouting
Phenotypes for gene: SLC38A8 were changed from Foveal hypoplasia 2, with or without optic nerve misrouting and/or anterior segment dysgenesis, 609218 to Foveal hypoplasia 2, with or without optic nerve misrouting and/or anterior segment dysgenesis OMIM:609218; foveal hypoplasia - optic nerve decussation defect - anterior segment dysgenesis syndrome MONDO:0012216
Publications for gene: SLC38A8 were set to 24290379; 24045842; 15466012; 24290379; 24045842
Source NHS GMS was added to SLC38A8. Rating Changed from Green List (high evidence) to Green List (high evidence)
This gene has been classified as Green List (High Evidence).
Mode of inheritance for SLC38A8 was changed to BIALLELIC, autosomal or pseudoautosomal
Publications for SLC38A8 were set to 24290379; 24045842; 15466012; 24290379; 24045842
Phenotypes for SLC38A8 were set to Foveal hypoplasia 2, with or without optic nerve misrouting and/or anterior segment dysgenesis, 609218
SLC38A8 was added to Posterior segment abnormalitiespanel. Sources: Literature
SLC38A8 was created by mgt14