We present a case of a 53-year-old Caucasian female patient. When she was 42 years old, falls and loss of balance occurred. Furthermore, at the age of 48, progressive, involuntary, uncoordinated movements of the upper limbs and head, tongue stereotypes (licking and extending movements), speech problems (dysarthria), memory deterioration, and hearing loss occurred. Since childhood, she has shown skin and conjunctiva hypersensitivity to the sun. She underwent splenectomy due to spherocytosis at the age of 18 and cholecystectomy at the age of 20. Before the age of 40, she was diagnosed with premature ovarian failure. In vitro fertilization was performed with a donor oocyte. She gave birth to a female baby. There was no family history of genetic diseases and consanguineous parents. She pursued philological education. Initially, she had been working as a teacher of the Russian language and then in a library. Currently, she is living on a pension. The neurological examination revealed chorea syndrome, cerebellar ataxia, dysarthria, and bilateral hearing loss. She has numerous pigmented lesions on her brown-colored skin (Figure 1). Brain MRI demonstrated massive cortico-subcortical atrophy (Figures 2, 3 ). The consulting otolaryngologist diagnosed bilateral sensory hearing impairment. The electroneurographic examination did not reveal any signs of peripheral polyneuropathy. Laboratory tests showed the presence of macrocytic anemia, significant vitamin B12 deficiency, and high levels of homocysteine. The consulting hematologist recommended supplementation with vitamin B12, iron, and folic acid. Endoscopic examination showed atrophic gastropathy. At the age of 48, a neuropsychological examination was performed which revealed cognitive-behavioral disorders with a predominance of subcortical symptomatology. Additionally, a slowdown in the pace of work, periodic drops in the tension of free attention, difficulties in organizing complex visual materials, and deficits in learning and memory, mainly of an executive nature, were described. The neuropsychological examination performed at the age of 53 revealed dysfunctions in the executive domain in the field of attention (maintenance, selectivity, and divisibility), working memory, organizing, and planning activities (mainly activities on visual materials). There was variability in the severity of dysfunction in the cognitive and non-cognitive spheres. The clinical details are presented in Table 1. The genetic diagnostics was performed which excluded spinocerebellar ataxia types 1, 2, 3, 6, and 17, Huntington's disease, and FMR1 premutation. Exome sequencing using the next-generation sequencing (NGS; SureSelectXT Human All Exome v7 (Agilent)) method was performed in further genetic diagnostics as previously described. Two variants in the ERCC4 gene, namely, missense c.2395C > T and a novel non-sense c.1349G > A, in the configuration of the heterozygote, were identified (Table 2). The presence of the c.1349G > A variant of the ERCC4 gene was found in a heterozygous state in the proband's mother but excluded in the father, while the presence of the c.2395C > T variant of the ERCC4 gene was found in a heterozygous state in the proband's father but excluded in the mother. It is consistent with in trans variant transmission in the autosomal recessive mode of inheritance. Moreover, in the proband, a heterozygous non-sense variant in the SPTB gene (hg38 chr14:064786837-C>T; NM_001355436.2:c.3128G>A (p.Trp1043Ter), rs1594775390) was identified (Figure 4). The c.3128G > A variant has 0 frequency in the gnomAD v3.1.2 database and was described in the ClinVar database as "pathogenic" and classified as "pathogenic" according to ACMG classification (total score 11, PVS1 very strong, PP5 moderate, and PM2 supporting). Variants in the SPTB gene, including the c.3128G > A variant identified in our patient, are associated with spherocytosis type 2, 8, and 9. The parents showed no clinical or laboratory signs of spherocytosis. So far, a rare phenotype of progressive spinocerebellar ataxia, chorea, cognitive impairment, and hearing loss with a history of skin photosensitivity has been described in single patients with ERCC4 gene variants.