Current Pediatric Research

Down syndrome (DS) is one of the most common chromosomal abnormalities, which is associated with various unique physical

traits and developmental delay. As the mortality rate of people with DS has declined, life expectancy at birth of people with DS was

increased between recent 50 years. Life expectancy for the time period of 1953 to 2000 was 58.6 year, compared with 16.2 years for

the period of 1948 to 1957 among those registered in a DS database in Western Australia. In Japan, the life expectancy for 1,052 DS

who were born between 1966 and 1975 increased to 48.9 years. In Western Australia, in contrast to female longevity in the general

population, males with DS were found to have significantly longer life expectancies, compared with their female counterparts. We

investigated sex differences in congenital heart disease (CHD), which may be related to mortality using data on 1310 people with DS

(626 females and 684 males) in Japan from five hospitals’ medical records and questionnaires completed by parents of people with

DS. The CHD rate was significantly higher for females (354, 57%) than for males (338, 49%; p=0.010). Significantly more females

(199, 32%) than males (175, 26%) underwent surgery for CHD (p=0.018). Higher prevalence and greater severity of CHD in females

may contribute to poor prognoses. We found that the most common cardiac anomalies (main lesions) were VSD, ASD, AVSD, PDA

and TOF, which together accounted for 95.5% of all CHD cases. Among people with DS born before 1979, in the1980s or 1990s,

we found that significantly more female than male subjects had CHD, but we found no significant sex difference for subjects born

in 2000 or later. Many factors seem to have contributed to this change, including the improvement of diagnostic techniques, such as

echocardiographic examination, and improvements in heart surgery. This shift may be attributed to a great increase in the diagnosis

of less severe CHD for both sexes. Improvements in quality of life of individuals with DS have resulted from prognosis in medical

care, identification and treatment of CHD in perinatal and postnatal period.