Clinical features in a patient with Turner syndrome and pericentric inversion of chromosome 9

Turner syndrome (TS) patients are at risk for a constellation of neurocognitive and psychosocial diseases. TS is associated with an increased risk for difficulties with visual–spatial reasoning, visual– spatial memory, attention, executive functioning, motor, and math skills. Additionally, increased rates of social difficulties, anxiety, and depression are observed. Here we report the case of a 16-years-old Caucasian girl who came to our attention at the age of 18 months due to short stature and clinical signs typical of TS. Genetic testing showed a single X chromosome and a pericentric inversion of chromosome 9 [45,X,inv(9) karyotype]. Imaging revealed no cardiovascular malformations and/or renal abnormalities. To date no autoimmune diseases have been detected.  At the time of diagnosis she presented a mild mental retardation. During the follow-up her parents did not attend educational programs prescribed by the neuropsychiatry specialist, and the patient developed a severe emotional disturbance with anxiety and a behaviour pattern characterized by complete language impairment. This behavioural phenotype was consistent with a diagnosis of autism spectrum disorder. Inv(9)(p11q13) is the most commonly observed structurally balanced rearrangement of chromosome involving the heterochromatic region. The estimated frequency varies from 1 to 4%. Although it is widely debatable, most cytogeneticists believe that this variant is a chromosomal polymorphism of the normal human karyotype without any clinical significance. Contradictorily, many clinical investigators have suggested several associations of inv(9) with clinical diagnoses, particularly with idiopathic reproductive failure, schizophrenia, and behavioural and neurodevelopmental disorders.  The association of this rearrangement in our patient could explain the severe neurodevelopmental disorder. On the basis of our observation we stress the importance to evaluate eventual associated chromosomal abnormalities in TS patients in order to predict certain phenotypic features of these individuals. As in our patient, the presence of pericentric inversion of chromosome 9 could increase the risk of developing neuropsychiatric disorders. According to the most recent literature, we think that the early identification of psychosocial disease may facilitate the improvement of social deficits through the prompt application of appropriate educational strategies and therapeutic programs.