Evaluation of clinical and laboratory findings of individuals with down syndrome, 11 years of experience

Down syndrome occurs in 1 in 800 live births in the community and is the most common genetic cause of intellectual disability. 96% of Down syndrome cases are classic (regular) Down syndrome, 3-4% are translocation type and 1-2% are mosaic type. <1% of cases develop due to partial trisomy. The most important known risk factor for regular Down syndrome is advanced maternal age. Individuals with Down syndrome are at increased risk for have congenital heart disease, anal atresia, congenital hypothyroidism, Hashimoto's thyroiditis, Graves' disease, celiac disease, type 1 diabetes, atlantoaxial instability, joint laxity, feeding problems, hearing loss, otitis media, sleep apnea, vision problems, skin problems, transient abnormal myelopoiesis, acute myeloid leukemia, and acute lymphoblastic leukemia. In this study, 264 individuals with Down syndrome whose first application to our clinic were between 01.01.2010-31.12.2020 are included. Prenatal, natal, postnatal, medical and surgical treatment histories, demographic characteristics and clinical, laboratory and radiological findings were evaluated retrospectively. It was determined that 97% of individuals with Down syndrome had regular type, 2.3% had translocation type and 0.7% had mosaic type Down syndrome. Maternal age is 35 and over in 48.8% of individuals whose maternal age data are available. Congenital heart disease was detected in 71.8% of individuals with Down syndrome, with secundum ASD being the most common. Overt or subclinical hypothyroidism was found in 33.7% of individuals with Down syndrome, and it was observed that 82% of those with overt hypothyroidism had congenital hypothyroidism. It has been found that 14% of individuals with Down syndrome have hearing loss, which 77.7% of them are conductive hearing loss. A history of otitis media was found in 12.6% of individuals with Down syndrome. Sleep apnea was found in 95.6% of individuals with Down syndrome who underwent polysomnography. A correlation was found between the history of otitis media and sleep apnea. A history of recurrent pneumonia was found in 12.5% of individuals with Down syndrome, which correlates with congenital heart disease, high congenital heart disease class and immunologic parameter impairment. Transient abnormal myelopoiesis was seen in 6.1% of individuals with Down syndrome, acute lymphoblastic leukemia in 1.2% and acute myeloblastic leukemia in 1.6%.