53-Pound baby's video is going viral since March. To date, it has already been viewed by over 21 million people and the reason for the massive interest of the public is, the baby is not simply obese, she was named as the world's heaviest baby girl.

53-Pound baby is Aliya Saleem. She was born weighing 9 pounds and since her fourth month, she started to rapidly gain weight, about 2-3 kilos per week. Now, at only 18 months, she hit the 53-pound mark on the scales.

The baby was brought to the pediatrician by her parents — Shabnam Parveen and Mohammad Saleem — ecause they are really puzzled as Aliya's hunger never ends. They would like to find answers on why their daughter continues to grow big and eat beyond normal.

What is causing Aliya to gain weight rapidly?

The pediatrician at the Orchid Medical Center in India, Dr. Bhavya Kumar, did not give a specific diagnosis on the girl's condition just yet but he presented a number of possibilities behind the baby's abnormal growth and appetite.

The most plausible diagnosis that the doctor stated was that Aliya seems to be suffering from a rare disorder called Prader Willi Syndrome. He thinks so because the girl has all the indications pointing to the disease like abnormalities in growth, obsessive eating habits, and learning difficulties.

Dr. Kumar further explained why he is looking at Prader Willi for baby Saleem's case by saying, "There could be some hormonal imbalance, there could some metabolic disease. There can be some genetic causes. It could be because of some tumor. But because there is a history of sibling loss with similar complaints, that points towards a genetic cause. So, I strongly suspect that this could be a case of some genetic disorder, most probably Prader Willi syndrome, which is a very rare disorder."

But then again, the medical expert stressed that they needed to run more tests to properly and accurately diagnosed what is wrong with Aliya. The neonatologist relayed that they are planning to test her hormones as well as see if her organs are functioning well.

The heaviest girl in the world will also be screened for diabetes and any thyroid malfunctioning. Further, an MRI scan, series of x-rays and ultrasound will also be done on her for complete testing.

The doctor said that the procedures would be carried so "that would rule out any genetic causes. And only after doing all those things, we would be probably able to make the diagnosis and then we can take it further from there."

In any case, the parents revealed that they are having a hard time keeping up with their daughter's appetite because she is hungry all the time. And with her weight, they almost couldn't lift her up too.

But more than the financial and other issues that come with Aliya's condition, what's bothering the girl's parents is the fact that one of their child has died due to the same symptoms as their 18-month old daughter.

"We are scared. Simran kept gaining weight all the time. Just like her, Aliya is also growing. So if we leave her untreated, we fear for the worst,' Mrs Parveen, the mother concluded.