The Phenotypic and Mutational Spectrum of the FHONDA Syndrome and Oculocutaneous Albinism: Similarities and Differences

Charlotte C Kruijt, Libe Gradstein, Arthur A Bergen, Ralph J Florijn, Benoit Arveiler, Eulalie Lasseaux, Xavier Zanlonghi, Laura Bagdonaite-Bejarano, Anne B Fulton, Claudia Yahalom, Anat Blumenfeld, Yonatan Perez, Ohad S Birk, Gerard C de Wit, Nicoline E Schalij-Delfos, Maria M van Genderen

Onderzoeksoutput: Bijdrage aan wetenschappelijk tijdschrift/periodieke uitgaveArtikelWetenschappelijkpeer review

21 Downloads (Pure)

Samenvatting

Purpose: The purpose of this study was to further expand the mutational spectrum of the Foveal Hypoplasia, Optic Nerve Decussation defect, and Anterior segment abnormalities (FHONDA syndrome), to describe the phenotypic spectrum, and to compare it to albinism.

Subjects and Methods: We retrospectively collected molecular, ophthalmic, and electrophysiological data of 28 patients molecularly confirmed with FHONDA from the Netherlands (9), Israel (13), France (2), and the United States of America (4). We compared the data to that of 133 Dutch patients with the 3 most common types of albinism in the Netherlands: oculocutaneous albinism type 1 (49), type 2 (41), and ocular albinism (43).

Results: Patients with FHONDA had a total of 15 different mutations in SLC38A8, of which 6 were novel. Excluding missing data, all patients had moderate to severe visual impairment (median visual acuity [VA] = 0.7 logMAR, interquartile range [IQR] = 0.6-0.8), nystagmus (28/28), and grade 4 foveal hypoplasia (17/17). Misrouting was present in all nine tested patients. None of the patients had any signs of hypopigmentation of skin and hair. VA in albinism was better (median = 0.5 logMAR, IQR = 0.3-0.7, P 0.006) and the phenotypes were more variable: 14 of 132 without nystagmus, foveal hypoplasia grades 1 to 4, and misrouting absent in 16 of 74.

Conclusions: Compared to albinism, the FHONDA syndrome appears to have a more narrow phenotypic spectrum, consisting of nonprogressive moderately to severely reduced VA, nystagmus, severe foveal hypoplasia, and misrouting. The co-occurrence of nystagmus, foveal hypoplasia, and misrouting in the absence of hypopigmentation implies that these abnormalities are not caused by lack of melanin, which has important implications for understanding the pathogenesis of these features.

Originele taal-2Engels
Pagina's (van-tot)19
TijdschriftInvestigative Ophthalmology & Visual Science
Volume63
Nummer van het tijdschrift1
DOI's
StatusGepubliceerd - 2022

Vingerafdruk

Duik in de onderzoeksthema's van 'The Phenotypic and Mutational Spectrum of the FHONDA Syndrome and Oculocutaneous Albinism: Similarities and Differences'. Samen vormen ze een unieke vingerafdruk.

Citeer dit