Sclerotylosis

Basan syndrome is a rare ectodermal dysplasia, characterised by adermatoglyphia, mottled acral pigmentation and various nail abnormalities; in addition to transient neonatal findings of acral blistering and facial milia. The genetic basis was established recently as heterozygous mutations affecting the skin specific isoform of the SMARCAD1 gene. It is now considered to be part of the spectrum of disorders resulting from haploinsufficiency of this isoform, which also includes Huriez syndrome and autosomal dominant adermatoglyphia. Here, we describe a family with Basan syndrome from South-India with a novel SMARCAD1 variant [SMARCAD1: c.-10 + 4_-10 + 7del] affecting the known mutational hotspot in non-coding exon 1.

This prospective study investigates longitudinal changes in retinal structure in patients with achromatopsia (ACHM) using optical coherence tomography (OCT).

Seventeen patients (five adults, 12 children) with genetically confirmed CNGA3- or CNGB3-associated ACHM underwent ocular examination and OCT over a follow-up period of between 2 and 9.33 years (mean = 5.7 years). Foveal tomograms were qualitatively graded and were segmented for quantitative analysis: central macular thickness (CMt), outer nuclear layer thickness (ONLt), and size of the foveal hyporeflective zone (vertical HRZ thickness: HRZt and horizontal HRZ width: HRZw) were measured. Data were analyzed using linear mixed regression models. Both age and visit were included into the models, to explore the possibility that the rate of disease progression depends on patient age.

Fifteen of 17 patients (88%) showed longitudinal changes in retinal structure over the follow-up period. The most common patterns of progression was development of ellipsoid zone (EZ) disruption and HRZ. There was a significant increase in HRZt (P = 0.01) and HRZw (P = 0.001) between visits and no significant change in CMt and ONLt. Retinal parameters showed no difference in changes by genetic mutation (CNGA3 (n = 11), CNGB3 (n = 6)).

This study demonstrates clear longitudinal changes in foveal structure mainly in children, but also in adults with ACHM, over a long follow-up period. The longitudinal foveal changes suggest that treatment at an earlier age should be favored.