You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Variant", "Disease", "Species", "CellLine", "Chemical", "Gene"].

Please return the output as a JSON object of the format: {"CellLine": ["hRPTEC", ...], "Chemical": ["Glucose", ...], "Disease": ["Diabetes", ...], "Gene": ["HNF-6", ...], "Species": ["Patients", ...], "Variant": ["Pro75Ala", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Skewed X inactivation in an X linked nystagmus family resulted from a novel, p.R229G, missense mutation in the FRMD7 gene. 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.
{"CellLine": [], "Chemical": [], "Disease": ["X linked NYS", "X linked nystagmus", "NYS", "genetic defect"], "Gene": ["FRMD7", "androgen receptor"], "Species": [], "Variant": ["arginine at amino acid position 229 by glycine", "p.R229G", "c.686C\u003eG", "CAG repeat"]}