Superman Syndrome is an XYY genetic condition in which a male has an extra Y chromosome rather than the conventional XY. This syndrome is classified as a chromosomal aneuploidy, essentially meaning an abnormality in the chromosome structure or number. Males and females have 46 chromosomes, however, with most sex-linked aneuploidies superman syndrome adds an additional chromosome, therefore the affected individual has 47 instead. 1 in every 850 males is affected by this disorder the symptoms range from extreme to severe and is variant case by case. 

The XYY karyotype has been associated with neurodevelopmental disorders, the most prevalent being autism. Life expectancy for an XYY individual is also significantly lower as most live up to 68 years. Difficulty in school primarily with reading and writing is also common among those who suffer from this disorder. Scientists have suspected that XYY males may pose larger risks of infertility and also present with increased sperm chromosomal abnormalities that they can pass on to offsprings. 

This disease has a lot of myths associated with it, as in previous years it was suspected that overly aggressive males or serial killers had this disorder. Scientists have been able to prove that individuals with XYY disorder are naturally more aggressive and that aggressiveness is developed through other factors (family life, social interactions etc.).  Doctors recommend that children partake in speech therapy and tutoring to tackle the difficulties that come with this disorder. Luckily, it is typically not life-threatening and most males tend to live long healthy lives. 

Symptoms are subtle and it is not necessary if a male has these symptoms that they have the XYY chromosome. There are many cases where individuals do not get a diagnosis or are misdiagnosed due to it being difficult to detect in milder cases. Phenotype (physical appearance) is typically normal besides a few minor things such as tall height which becomes noticeable around the ages of 5-6. Most males suffer from severe cystic acne that starts earlier than when most adolescents develop it. Issues with fertility and sexual development are also common, but not usually severe. Studies have shown that XYY males have an IQ 10 points lower than their peers, and they may require extra work/time to fully develop (mentally).  Up to 55% of cases have shown issues with speech, both talking and understanding as well as delays in overall neurodevelopment. 

Symptoms and Signs

• Taller than average height 
• Muscles weakness 
• Hypertelorism (wide-spaced eyes)
• Clinodactyly (curved fingers)
• Asthma 
• Cystic Acne at a young age