Clinical features and linkage analysis for a Chinese family with autosomal dominant central areolar choroidal dystrophy.

BACKGROUND: A Chinese family with autosomal dominant central areolar choroidal dystrophy (CACD) was identified. The purpose of this study was to collect the clinical findings from the family and to identify the genetic entity by linkage analysis. METHODS: Forty-three individuals from 3 generations of the family underwent ophthalmologic examinations, including best-corrected visual acuity, examination of the anterior segments, and inspection of the ocular fundus after pharmacologic mydriasis. Affected family members further underwent color vision test, color fundus photography, fluorescein angiography, automated perimetry, and electroretinography. The family was followed up for 30 months. Peripheral venous blood or buccal swabs were collected from each family member and genomic DNA was extracted. Linkage analysis was performed for candidate genes or loci using microsatellite markers. RESULTS: Seven family members in 3 continuous generations were diagnosed as having autosomal dominant CACD. The family showed progressive development of the disease, affecting both male and female. Age of onset of visual disturbances varied between 11 and 50 years. Phenotypic variability among affected individuals was apparent and ranged from relatively normal-appearing fundus with mild parafoveal pigment mottling to geographic atrophy of the macula. Fluorescein angiography showed hyperfluorescent parafoveal changes in early stage or well-demarcated area of chorioretinal atrophy with enhanced visibility of the residual underlying choroidal vessels in the late stage. Peripheral retina and visual fields were normal in affected individuals. Electroretinogram showed normal or mild reduction in the photopic amplitude. Eight candidate genes (STGD4, RCD1, peripherin/RDS, GUCA1A, RIMS1, UNC119, GUCY2D, and AIPL1) and two genetic loci (4p15.2 - 16.3, and 17p13) were excluded to be responsible for the disease by linkage analysis. CONCLUSIONS: The clinical findings of this Chinese family with CACD shared similarities with previously reported families of other ethnicities. Linkage analysis excluded the known genes and genetic loci, indicating genetic heterogeneity of the disease.

[Molecular identification of wheat granule bound starch synthase gene polymorphism].

Fourteen wheat cultivars were identified into six types of Wx proteins combinations using 6% SDS-PAGE. PCR primers were designed according to the three Wx genes sequences and their mutants, respectively. A 327 bp-band was amplified from the Wx-A1 mutant,while the band was absent for the normal alleles at the Wx-A1 locus,as well as the presence or absence of a 187 bp PCR fragment at the Wx-B1 locus and a 700 bp PCR fragment at the Wx-D1 locus, respectively, corresponding to the normal and mutant alleles. Compared with the former studies, shorter and more different PCR products at three loci, amplified by the primers designed for Wx-B1 gene can be separated in 2% agarose gel, which enables screening breeding lines for noodle use faster and effectively.

[Development and application of a genome specific PCR marker for Haynaldia villosa].

Random amplified polymorphic DNA (RAPD) analysis was performed on common wheat Chinese Spring, H. villosa, addition lines of H. villosa chromosome in CS, substitution line 3V of H. villosa chromosome in Triticum aestivum. A genome specific polymorphic DNA segment from H. villosa, OPF02757, was obtained. On the basis of cloning and sequencing of OPF02757, two PCR primers were designed and a genome specific PCR marker for H. villosa was established. The PCR marker including 677 bp was localized on all the seven pairs of H. villosa chromosomes. The result of PCR amplification by the primers indicated that there was a specific band of 677 bp in the materials containing H. villosa Chromosome such as T. aestivum-H. villosa addition, T. aestivum-H. villosa substitution, T. aestivum-H. villosa amphidiploid, T. durum-H. villosa amphidiploid and H. villosum from different accessions, and there was no specific band of 677 bp if the materials did not contain H. villosa chromosome, such as T. aestivum, T. durum, Secale cereale, Hordeum vulgare, Thinopyrum elongatum, Thinopyrum intermedium. Therefore, the PCR maker of 677 bp is specific to H. villosa genome, and could be used as molecular marker for detection of chromosomes of H. villosa in wheat.

[Identification, mapping, and application of a chromosome-specific RAPD marker from Haynaldia villosa].

Random amplified polymorphic DNA (RAPD) analysis was performed on common wheat of Chinese Spring, addition lines of H. villosa chromosome in CS and H. villosum from different accessions with 100 random 10-base primers. A chromosome-specific polymorphic DNA segment for H. villosa, OPF02(750), was obtained from all addition lines of H. villosa chromosome in CS and H. villosum which belong to different accessions. The result amplified by primer OPF02 of all addition lines of H. villosa chromosome in CS indicated that all the seven pairs of H. villosa chromosomes contain OPF02(750) segment. There was no OPF02(750) in all Triticum aestivum and T. durum tested. Using OPF02, We confirmed that NAU302, an addition line of H. villosa chromosome 3V, had lost its chromosome 3V of H. villosa. Therefore, OPF02(750) is specific to chromosomes of H. villosa, and could be used as a molecular marker for detection of chromosome of H. villosa in wheat.