Heterozygous mutations of the kinesin KIF21A in congenital fibrosis of the extraocular muscles type 1 (CFEOM1).

Congenital fibrosis of the extraocular muscles type 1 (CFEOM1; OMIM #135700) is an autosomal dominant strabismus disorder associated with defects of the oculomotor nerve. We show that individuals with CFEOM1 harbor heterozygous missense mutations in a kinesin motor protein encoded by KIF21A. We identified six different mutations in 44 of 45 probands. The primary mutational hotspots are in the stalk domain, highlighting an important new role for KIF21A and its stalk in the formation of the oculomotor axis.

Older age and larger cyst size in children with spontaneous rupture of periorbital dermoid cysts.

We analyzed clinical and histopathologic data of 97 pediatric patients who underwent excision of dermoid cysts. On review, 16.5% of the sample population demonstrated localized chronic inflammatory changes, including the presence of giant cells and epithelial disruption. These features were considered indicative of prior cyst rupture. Age at time of initial presentation was significantly older and cyst size was significantly larger in patients with histopathologic signs of previous rupture. Longer time to presentation and time to excision were associated with increased odds of spontaneous rupture.

Congenital cystic eye: recurrence after initial surgical removal.

Congenital cystic eye arises from failure of invagination of the primary optic vesicle. The cyst lacks the usual intraocular structures and contains only abortive derivatives of the anterior and posterior portions of the primary optic vesicle. Because the cystic eye usually occupies a large portion of the orbit and distends the upper eyelid, surgical excision is often carried out. We report a case of congenital cystic eye in which an initial attempt at excision was followed in three months by recurrence of the cyst in the orbit. A second excision appears to have eliminated the cyst since no recurrence has become evident in the ensuing two years. The pathology of the cyst from both excision specimens suggests that the pigmented cells from the posterior portion of the cyst were not included in the first resection. Based on this experience, we conclude that every effort should be made to excise all of the congenital cystic eye when surgical removal is undertaken.

Developmental conjunctival cyst of the eyelid in a child.

Conjunctival cysts unrelated to surgery or trauma are uncommon adnexal lesions in children and may be difficult to recognize. We report the clinical and pathological findings of an apparently spontaneous conjunctival cyst in the upper eyelid of a child whose first ophthalmological examination was at 7 months of age. The cyst was surgically excised at 5 years of age.

Alzheimer's disease amyloid-beta links lens and brain pathology in Down syndrome.

Down syndrome (DS, trisomy 21) is the most common chromosomal disorder and the leading genetic cause of intellectual disability in humans. In DS, triplication of chromosome 21 invariably includes the APP gene (21q21) encoding the Alzheimer's disease (AD) amyloid precursor protein (APP). Triplication of the APP gene accelerates APP expression leading to cerebral accumulation of APP-derived amyloid-beta peptides (Abeta), early-onset AD neuropathology, and age-dependent cognitive sequelae. The DS phenotype complex also includes distinctive early-onset cerulean cataracts of unknown etiology. Previously, we reported increased Abeta accumulation, co-localizing amyloid pathology, and disease-linked supranuclear cataracts in the ocular lenses of subjects with AD. Here, we investigate the hypothesis that related AD-linked Abeta pathology underlies the distinctive lens phenotype associated with DS. Ophthalmological examinations of DS subjects were correlated with phenotypic, histochemical, and biochemical analyses of lenses obtained from DS, AD, and normal control subjects. Evaluation of DS lenses revealed a characteristic pattern of supranuclear opacification accompanied by accelerated supranuclear Abeta accumulation, co-localizing amyloid pathology, and fiber cell cytoplasmic Abeta aggregates (approximately 5 to 50 nm) identical to the lens pathology identified in AD. Peptide sequencing, immunoblot analysis, and ELISA confirmed the identity and increased accumulation of Abeta in DS lenses. Incubation of synthetic Abeta with human lens protein promoted protein aggregation, amyloid formation, and light scattering that recapitulated the molecular pathology and clinical features observed in DS lenses. These results establish the genetic etiology of the distinctive lens phenotype in DS and identify the molecular origin and pathogenic mechanism by which lens pathology is expressed in this common chromosomal disorder. Moreover, these findings confirm increased Abeta accumulation as a key pathogenic determinant linking lens and brain pathology in both DS and AD.