Pseudogenes are genomic regions that contain gene-like sequences that have a high similarity to the known genes but are nonfunctional. They are categorized into processed, unprocessed, and unitary pseudogenes. Unprocessed pseudogenes generated by duplications can be problematic in sequencing approaches in molecular diagnostics. We discuss the risk of misdiagnosis when investigating genes with pseudogenes of high homology, and describe a method for identifying these small and annoying differences between parent genes and pseudogenes, including parent gene-specific assay design.

Klinefelter's syndrome (KS) is a syndrome with extra X chromosome(s), in XY individuals, characterized by gynecomastia, small testes, and infertility. Additional X chromosomes can be present as variable karyotypic forms, including mosaicism (47,XXY/46,XY). The reported prevalence of KS ranges from one in 500 to one in 1,000 live males, but is probably underestimated. The classic phenotype is small, firm testes and infertility resulting from seminiferous tubule dysgenesis and androgen deficiency. The spectrum of KS includes tall stature with relatively long legs and arm span, decreased body hair, learning disabilities, behavioral problems, poor motor skills, and other important medical issues, such as metabolic syndrome, diabetes, autoimmune diseases, cardiovascular disease, certain neoplasia. The increased risk of certain medical problems in KS can be attributed to a direct effect of the extra X chromosome, the combined action of multiple genomic and epigenetic factors, or the hormonal imbalances. Typically, chromosome analysis is not ordered for adult patients with general medical conditions, except for suspected cases of hematologic and lymphoid disorders. Even though it was found during work-up for certain disorders in adult patient, most physicians do not suspect KS or consider its impact. Therefore, understanding the pathophysiology and variable manifestation in KS is necessary, and discussions with multidisciplinary teams will help to diagnose and treat males with KS.

Background: Arteriovenous malformations (AVMs) are rare diseases comprising abnormally dilated arteries and veins with an absence of a capillary network. Since these diseases are intractable after diagnosis, various treatment strategies have been examined, with continuous efforts to identify target genes. Here, we report relevant new target genes selected via gene microarray. Methods: Endothelial cells were isolated from samples collected from three patients with AVM and three healthy individuals, followed by microarray analysis. Additionally, quantitative PCR was performed to select genes highly relevant to AVM. Results: In the vascular endothelial cells derived from the tissues of patients with AVM, the expression of ANGPT1, ANGPT2, DLL4, IL6, NRG1, TGFBR1, and VEGFA was typically higher compared to those derived from normal tissues. Conclusion: Seven candidate genes were selected to analyze the pathophysiological mechanism of AVM. These results may aid in future directions of diagnosis and treatment.

Background: Prader-Willi syndrome (PWS) is a complex genetic disease associated with growth impairment, severe obesity and metabolic dysfunctions. High proportion of PWS patients are born small for gestational age (SGA) than normal children, which also increase the risk of growth impairment and metabolic dysfunction in PWS. We aimed to compare growth outcome and metabolic profiles between SGA and appropriate for gestational age (AGA) PWS patients. Methods: Data of 55 PWS children and adults aged more than 2 years old (32 male and 23 female, age 2-18.8 years) from single center were studied. Only patients who were treated with GH were included. The clinical characteristics and laboratory findings were reviewed retrospectively. Results: Among 55 subjects, 39 had 15q11-13 deletion and 16 had uniparental disomy (UPD). Twenty (36.3%) were born SGA. All patients received GH treatment, and 11 (20%) discontinued GH treatment. Mean age at GH treatment initiation was 2.5 (range 0.3-12.4) years, and mean duration of treatment was 6.3 (range 1.0-11.3) years. Current height-SDS (-0.36 vs -0.16) and BMI-SDS (1.44 vs 1.33) did not differ between AGA and SGA group. Two patients in SGA group, but none in AGA group had diabetes mellitus. Mean glucose level was also higher in SGA group (100.1 vs 114.4 mg/dL). Conclusion: Our report gives an overview of growth profile and metabolic dysfunctions recorded in GH treated PWS patients. Growth profile did not differ between AGA and SGA group. Glucose level was higher in SGA group, so more careful monitoring and prevention for DM will be required in SGA group.