Usher syndrome in four Norwegian counties

Abstract

Among 89 probands selected for tapeto‐retinal degeneration, 18 (20%) were given the diagnosis of Usher syndrome. Among the relatives of the probands another 10 cases of Usher syndrome were found. The distribution on type diagnoses was: Usher syndrome type I: 14 cases, type II: 10 cases and type III: four cases. The pattern of inheritance was autosomal recessive for 12 families, and the remaining six probands were solitary cases without consanguinity between the parents. There was a high intrafamiliar correlation with respect to hearing function, indicating genetic heterogeneity in Usher syndrome. Obligate heterozygotes did not demonstrate heterozygote manifestation. One man with Usher syndrome type I was psychotic, the remaining 27 did not demonstrate serious psychic disturbances. Atactic gait was not observed, though vestibular response was abolished in three patients with Usher syndrome type I. Three patients with type II and one person with type III had normal vestibular response. The prognosis for visual function was not highly correlated to the type diagnosis or to the age when hemeralopia was first noticed. Visual function was good before 30 years of age and bad in most patients after the age of 50.

Children with Usher syndrome: mental and behavioral disorders

“…The types of disorders observed were not uniform and included atypical autism, mental retardation, schizophrenia, and conduct disorder. The number of individuals found with schizophrenia in this study (1 child) is congruent with results reported by Nuutila [15] and Grøndahl and Mjøen [14] using samples of 133 and 89 adults with Usher syndrome, respectively. Among the children without mental and behavioral disorders around one third was found to have psychosocial difficulties.…”

“…Schaefer and colleagues [40] found that the measured volume of the brain was significantly smaller compared to normal controls and Koizumi et al [10] found a global degeneration of the brain in one case with Usher syndrome and schizophrenia. Similar to the surveys by Nuutila [15] and Grøndahl and Mjøen [14] this study found that only some individuals with Usher syndrome had mental and behavioral disorders and the nomenclature of disorders was not uniform. Either different Usher genes are associated with different kinds of mental and behavioral disorders, or another explanation may be the necessary.…”

“…Psychosis (schizophrenic type picture) has been discussed in some case studies [4-12] and Hallgren [13] reported that 23% of 114 individuals with Usher syndrome were psychotic. However, Grøndahl and Mjøen [14] reported only one case of psychosis among 28 individuals with Usher syndrome and Nuutila [15] reported mere 4.5% of individuals with Usher syndrome to be psychotic in a study of 133 individuals. Mental retardation [16], anorexia nervosa [17] and ADHD [4] have also been discussed or reported upon in case-studies investigating Usher syndrome.…”

Usher syndrome in Denmark: mutation spectrum and some clinical observations

“…The prevalence has been estimated to be 3.5–16.6 in 100,000 (Boughman et al. ; Grondahl and Mjoen ; Rosenberg et al. ; Kimberling et al.…”

Mutation analysis of the MYO7A and CDH23 genes in Japanese patients with Usher syndrome type 1

“…[8][9][10] USH type 1 (USH1) is characterized by congenital severe-toprofound HL and vestibular dysfunction; it is the second common type after USH type 2 and accounts for 25-44% of the USH cases. 7,11 Five causative genes have been identified: myosin VIIA (HUGO gene symbol MYO7A); Usher syndrome 1C, harmonin (USH1C); cadherinrelated 23 (CDH23); protocadherin-related 15 (PCDH15); and Usher syndrome 1G, Sans (USH1G). [12][13][14][15][16][17][18] Mutations in these genes have been observed in patients with USH1 from various ethnic origins, including Caucasian, African and Asian.…”