Clinical case report: multiple idiosyncratic adverse effects of antiepileptic drugs in trisomy 9p

Molecular genetic analysis of partial 9p trisomy in two Chinese families with mental retardation and facial anomaly

Mental retardation is defined by significant limitations in intellectual function and adaptive behavior that occur before 18 years of age. Many chromosomal diseases come with mental retardation. We reported two Chinese families with partial trisomy 9p and other chromosome partial monosomy, clinical features of mental retardation and mild facial and pinkie anomalies. In the family 1, we showed that the proband carried a trisomy 9p21.3→pter and monosomy 21q22.3→qter by using fluorescence in situ hybridization analysis. Molecular genetic analysis defined the precise breakpoint on chromosome 9p between markers D9S1846 and D9S171, an interval of about 2.9 Mb on 9p21.3, and the breakpoint on chromosome 21q between markers D21S1897 and D21S1446, a region of about 1.5 Mb on 21q22.3. In the family 2, a patient with trisomy 9p21.3→pter and monosomy 5p15.33→pter, and a de novo maternal balanced translocation between chromosomes 5 and 9 was identified in his mother. Cytogenetic and molecular genetic analysis defined the precise breakpoints on chromosome 9p21.3 and chromosome 5p15.33. Further clinical investigation found that any individual had no refractoriness eczema disease except the proband in this family. These results further implicate that trisomy 9p is associated with mental retardation, and that there may be key gene duplication on chromosome 9p21.3→9pter responsible for mental retardation and mild facial anomaly. This result has been applied successfully in prenatal diagnosis of the second family.

Lupus-like disease and high interferon levels corresponding to trisomy of the type I interferon cluster on chromosome 9p

OBJECTIVE

Systemic lupus erythematosus (SLE) is associated with type I interferons (IFNs) and can be induced by IFNalpha treatment. This study looked for evidence of autoimmunity in a pedigree consisting of 4 family members with a balanced translocation 9;21 and 2 members with an unbalanced translocation resulting in trisomy of the short (p) arm and part of the long (q) arm of chromosome 9. These latter 2 subjects had 3 copies of the IFN gene cluster.

METHODS

Subjects were evaluated clinically and serologically for autoimmune disease. Expression levels of IFNalpha4, IFNbeta, the type I IFN-inducible gene Mx1, the type I IFN receptor, interleukin-6, and tumor necrosis factor alpha were determined by real-time polymerase chain reaction. Circulating plasmacytoid dendritic cells, the main IFN-producing cells, were quantified by flow cytometry.

RESULTS

Both subjects with trisomy of chromosome 9p had a lupus-like syndrome with joint manifestations and antinuclear antibodies: one had anti-RNP and antiphospholipid autoantibodies, and the other had anti-Ro 60. The 3 family members with a balanced translocation 9;21 had no clinical or serologic evidence of autoimmunity, similar to that in relatives who were unaffected by the chromosomal translocation. In the 2 subjects with trisomy of 9p, high levels of IFNalpha/beta (comparable with those found in patients with SLE), increased signaling through the IFN receptor (as indicated by high Mx1 expression), and low levels of circulating plasmacytoid dendritic cells (as observed in patients with SLE) were evident. These abnormalities were not seen in individuals with a balanced translocation.

CONCLUSION

Trisomy of the type I IFN cluster of chromosome 9p was associated with lupus-like autoimmunity and increased IFNalpha/beta and IFN receptor signaling. The data support the idea that abnormal regulation of type I IFN production is involved in the pathogenesis of SLE.

Hepatoblastoma in a patient with a partial trisomy 9p syndrome: a case report

After an uneventful pregnancy, a boy was born by vacuum extraction at 40.6 weeks' gestation. Physical examination revealed several malformations due to a partial trisomy 9p [karyotype: 46,XY, dup(9)(p13p24)]. Three months after birth, the boy presented with a hepatoblastoma without distant metastases which was treated with chemotherapy combined with surgery. At the last follow-up, 15 years after the resection of the hepatoblastoma, he was still in complete remission. To our knowledge this is the first case report of a patient with a constitutional partial trisomy 9p associated with hepatoblastoma.

[Trisomy 9p. Report of two new cases]

Trisomy 9p is a chromosome abnormality caused by duplication of the short arm of chromosome 9. Clinically it is characterized by psychomotor retardation, malformations that can affect various organs and sometimes epilepsy. Trisomy 9p may be the fourth most common autosomal trisomy, after trisomies 21, 13 and 18. Two new cases of trisomy 9p are described. Previous cases reported in Spain, associated clinical features, and the diagnostic and therapeutic approach to these patients are revised.

Anticonvulsant-induced dyskinesia

Anticonvulsant-induced dyskinesia (AID) is an underdiagnosed side effect of many anticonvulsants that may take place during initial or chronic treatment at normal or toxic drug levels. The occurrence of AID subjects the patient to another medical condition and may prompt an extensive work-up. Similarities with other drug-induced dyskinesias and some animal studies suggest that dopaminergic dysfunction in the basal ganglia is pivotal in the occurrence of dyskinesia. Clinical presentation and outcomes are variable; however, in most cases, dyskinesias respond well to anticonvulsant withdrawal. Enhancing the awareness of AID is important in light of the recent development of many new anticonvulsants and their wider clinical use.