In one study, 34 Turner syndrome girls without overt evidence of these tumors were found at preventative surgery to have a gonadoblastoma (7 cases), dysgerminoma (1 case), or non-specific in situ gonadal neoplasm (1 case). Turner syndrome girls with this sSMC otherwise have typical features of the Turner syndrome except for a minority who also have hirsutism and/or clitoral enlargement. Surgical removal of the gonads has been recommended to remove the threat of developing these sSMC-associated neoplasms. Tuner syndrome individuals with an sSMC that lacks the SRY gene are not at an increased risk of developing these cancers. Sensory
Hearing loss is common in Turner syndrome. Though at birth hearing is generally normal, chronic middle ear problems are frequent throughout childhood, which can cause permanent conductive hearing loss. In adulthood, sensorineural hearing loss occurs more often than in 46,XX women and at younger ages; though differing thresholds of hearing loss make it difficult to compare between studies, younger adult women with Turner syndrome are routinely found to have disproportionate rates of hearing issues, with sometimes up to half of women in their 20s and 30s having poor hearing. This hearing loss is progressive; at the age of 40, women with Turner syndrome have equivalent hearing loss to 46,XX women aged 60, on average. Cohort studies imply hearing loss may be more common in women who also have metabolic syndrome. The high prevalence of sensorineural hearing loss in Turner syndrome appears to be related to SHOX deficiency.Ocular and visual disorders are also increased in prevalence in Turner syndrome.
The gene is not present on Y chromosomes and in normal females resides on and functions to inactivate many of the genes located on its own maternal but not the fathers X chromosome. Turner syndrome females with (46,X,i(Xq) sSMC consisting of a partial X chromosome that does not contain the XIST gene express at least some of this sSMCs genetic material and therefore contain excesses of this material. In consequence, they have a more serious form of the Turner syndrome that ranges form moderately severe to extremely severe. The extremely severe cases have anencephaly (absence of a major portion of the brain, skull, and scalp), agenesis of the corpus callosum (lack of the thick tract of nerve fibers that connect the left and right cerebral hemispheres), and complex heart deformities. Individuals with Turner syndrome that have partial X chromosome containing(46,X,i(Xq) sSMCs that have the XIST gene do not express this sSMCs genetic material and do not have the more severe manifestations of the syndrome. Inheritance
In the majority of cases where monosomy occurs, the X chromosome comes from the mother. This may be due to a nondisjunction in the father. Meiotic errors that lead to the production of X with p arm deletions or abnormal Y chromosomes are also mostly found in the father. Isochromosome X or ring chromosome X on the other hand are formed equally often by both parents. Overall, the functional X chromosome usually comes from the mother.