Purpose
To describe atypical ocular manifestations and distinctive genetic aspects of a child with Hallermann Streiff syndrome(HSS). Hallermann Streiff is a very rare genetic disorder, with less than 200 cases described in medical literature. It is primarily characterised by ocular abnormalities, craniofacial malformations and mental retardation. GJA1 mutations located on chromosome 6 - 6q22.31 were encountered previously in some cases.
Methods
We performed detailed ophthalmologic examination of a ten year old child with HSS phenotype, which included biomicroscopy, ocular biometry, keratometry, tonometry and indirect ophthalmoscopy. Array comparative genomic hybridization (array-CGH) test was performed using a 135k cytogenetics (CGX) array; the copy number data was analysed.
Results
The child presented the following clinical features of HSS: bird head dyscephaly, frontal bossing, hypotrichosis, short stature, oligodontia and mental retardation. The ophthalmologic exam revealed microphthalmia, iris atrophy, blue sclera, microcorneea, aphakia, downslanting palpebral fissures, bilateral upper eyelid entropion, pendular nystagmus, esotropia and trichiasis. Indirect ophthalmoscopy revealed optic disc atrophy, peripapillary chorioretinal atrophy and retinal pigmented epithelium hyperplasia. Atypical ocular manifestations for HSS were band kerathopathy and thickened anterior hyaloid. Intraocular pressure values were normal. Genetic testing showed a 117 006 base pairs submicroscopic duplication located on the long arm of chromosome 16 - 16p12.1.
Conclusions
Our genetic results provide new genetic information on HSS, revealing a 16p12.1 microduplication which could also be related to mental retardation. The reported case presents particular ocular findings which raise even more difficulties in the course of ophthalmologic treatment. We suggest looking for uncommon manifestations like band kerathopathy and thickened anterior hyaloid when considering intraocular lens implantation.
Keywords: 539 genetics •
629 optic nerve •
488 crystallins