BackgroundHereditary short stature syndromes are clinically and genetically heterogeneous disorders and the cause have not been fully identified. Yakuts are a population isolated in Asia; they live in the far east of the Russian Federation and have a high prevalence of hereditary short stature syndrome including 3-M syndrome. A novel short stature syndrome in Yakuts is reported here, which is characterised by autosomal recessive inheritance, severe postnatal growth retardation, facial dysmorphism with senile face, small hands and feet, normal intelligence, Pelger-Huët anomaly of leucocytes, and optic atrophy with loss of visual acuity and colour vision. This new syndrome is designated as short stature with optic atrophy and Pelger-Huët anomaly (SOPH) syndrome.AimsTo identify a causative gene for SOPH syndrome.MethodsGenomewide homozygosity mapping was conducted in 33 patients in 30 families.ResultsThe disease locus was mapped to the 1.1 Mb region on chromosome 2p24.3, including the neuroblastoma amplified sequence (NBAS) gene. Subsequently, 33 of 34 patients were identified with SOPH syndrome and had a 5741G/A nucleotide substitution (resulting in the amino acid substitution R1914H) in the NBAS gene in the homozygous state. None of the 203 normal Yakuts individuals had this substitution in the homozygous state. Immunohistochemical analysis revealed that the NBAS protein is well expressed in retinal ganglion cells, epidermal skin cells, and leucocyte cytoplasm in controls as well as a patient with SOPH syndrome.ConclusionThese findings suggest that function of NBAS may associate with the pathogenesis of short stature syndrome as well as optic atrophy and Pelger-Huët anomaly.

The arrangement of connective tissue components (i.e., collagen, reticular, and elastic fibers) and glial elements in the optic nerve head of the human eye was investigated by the combined use of light microscopy and scanning electron microscopy (SEM). Light-microscopically, the optic nerve head could be subdivided into four parts from the different arrangements of the connective tissue framework: a surface nerve fiber layer, and prelaminar, laminar, and postlaminar regions. The surface nerve fiber layer only possessed connective tissue elements around blood vessels. In the prelaminar region, collagen fibrils, together with delicate elastic fibers, formed thin interrupted sheaths for accommodating small nerve bundles. Immunohistochemistry for the glial fibrillary acidic protein (GFAP) showed that GFAP-positive cells formed columnar structures (i.e., glial columns), with round cell bodies piled up into layers. These glial columns were located in the fibrous sheaths of collagen fibrils and elastic fibers. In the laminar region, collagen fibrils and elastic fibers ran transversely to the optic nerve axis to form a thick membranous layer - the lamina cribrosa - which had numerous round openings for accommodating optic nerve fiber bundles. GFAP-positive cellular processes also ran transversely in association with collagen and elastin components. The postlaminar region had connective tissues which linked the lamina cribrosa with fibrous sheaths for accommodating nerve bundles in the extraocular optic nerve, where GFAP-positive cells acquired characteristics typical of fibrous astrocytes. These findings indicate that collagen fibrils, as a whole, form a continuous network which serves as a skeletal framework of the optic nerve head for protecting optic nerve fibers from mechanical stress as well as for sustaining blood vessels in the optic nerve. The lamina cribrosa containing elastic fibers are considered to be plastic against the mechanical force affected by elevation of the intraocular pressure. The present study has also indicated that glial cells with an astrocytic character play an important role in constructing the connective tissue framework characteristic of the optic nerve head.

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GNAQ and GNA11 mutations are thought to be important for the tumorigenesis of uveal melanoma. Although previous studies have reported on mutation rates in cases of uveal melanoma, presently, no such report for the Japanese population exists. In this study, we examined the frequency of GNAQ and GNA11 somatic mutations in cases of uveal melanoma in Japan and their relationship with clinicopathologic features or Ki-67-positive cell rates (Ki-67 labeling index: Ki-67 LI) using immunofluorescence methods. The study involved 19 cases of uveal melanoma. We extracted the template DNA from formalin-fixed, paraffin-embedded specimens using a DNA extraction kit. We amplified the DNA sequences of GNAQ and GNA11 using polymerase chain reaction and analyzed mutations by direct sequencing. We evaluated Ki-67 LI using immunofluorescence methods. The frequencies of GNAQ and GNA11 somatic mutations were 26.3% (5/19) and 31.6% (6/19), respectively. The GNAQ and GNA11 mutations were mutually exclusive, as indicated in previous reports. The frequency of GNA11 mutations was significantly higher in epithelioid cells; however, no significant association between GNAQ mutations and cell type was evident, and there was no significant difference in Ki-67 LI between the mutation-positive and mutation-negative tumors. GNAQ and GNA11 mutations were identified in cases of uveal melanoma in Japan, although at lower frequencies than in white counterparts. The mutation frequency of GNA11 was significantly higher in epithelioid cells.

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