Skewed X inactivation in an X linked nystagmus family resulted from a novel, p.R229G, missense mutation in the FRMD7 gene
British Journal of Ophthalmology
135 - 141
Item Usage Stats
Aims: This study aimed to identify the underlying genetic defect of a large Turkish X linked nystagmus (NYS) family. Methods: Both Xp11 and Xq26 loci were tested by linkage analysis. The 12 exons and intron-exon junctions of the FRMD7 gene were screened by direct sequencing. X chromosome inactivation analysis was performed by enzymatic predigestion of DNA with a methylation-sensitive enzyme, followed by PCR of the polymorphic CAG repeat of the androgen receptor gene. Results: The family contained 162 individuals, among whom 28 had NYS. Linkage analysis confirmed the Xq26 locus. A novel missense c.686C>G mutation, which causes the substitution of a conserved arginine at amino acid position 229 by glycine (p.R229G) in exon 8 of the FRMD7 gene, was observed. This change was not documented in 120 control individuals. The clinical findings in a female who was homozygous for the mutation were not different from those of affected heterozygous females. Skewed X inactivation was remarkable in the affected females of the family. Conclusions: A novel p.R229G mutation in the FRMD7 gene causes the NYS phenotype, and skewed X inactivation influences the manifestation of the disease in X linked NYS females.
FRMD7 protein, human
Major clinical study
Polymerase chain reaction
X chromosome linked disorder
Non insulin dependent diabetes mellitus
X chromosome inactivation
X chromosome linked disorder
Diabetes Mellitus, Type 2
DNA Mutational Analysis
Eye Diseases, Hereditary
Genetic Diseases, X-Linked
X Chromosome Inactivation
Published Version (Please cite this version)http://dx.doi.org/10.1136/bjo.2007.128157
Showing items related by title, author, creator and subject.
Topçu, M.; Akyerli, C.; Sayi, A.; Törüner, G. A.; Koçoǧlu, S. R.; Cimbiş, M.; Özçelik, T. (Nature Publishing, 2002)Rett syndrome is a severe neurodevelopmental disorder that arises from mutations in the X-linked MECP2 gene. It is almost exclusively seen in girls due to the predominant occurrence of the mutations on the paternal ...
Chan, C.-C.; Scoggin, S.; Wang, D.; Cherry, S.; Dembo, T.; Greenberg, B.; Jin, E.J.; Kuey, C.; Lopez, A.; Mehta, S.Q.; Perkins, T.J.; Brankatschk, M.; Rothenfluh, A.; Buszczak, M.; Hiesinger P.R. (2011)Background: Neurons require highly specialized intracellular membrane trafficking, especially at synapses. Rab GTPases are considered master regulators of membrane trafficking in all cells, and only very few Rabs have known ...
Bagislar, S.; Ustuner, I.; Cengiz, B.; Soylemez, F.; Akyerli, C. B.; Ceylaner, S.; Ceylaner, G.; Acar, A.; Ozcelik, T. (Wiley-Blackwell Publishing Asia, 2006)Background: The role of extremely skewed X-chromosome inactivation (XCI) has been questioned in the pathogenesis of recurrent spontaneous abortion (RSA) but the results obtained were conflicting. Aims: We therefore ...