Laxmi and brother Azad with mum Parvati. Pic: NIKLAS HALLE'N / BARCROFT MEDIA
They have the bodies of young children. Standing 3ft tall and weighing 3 stone each, Azad Singh and sister Laxmi Yadav could be easily mistaken for five-year-olds.
But in fact, the siblings are 18 and 16 years old – and that is the way they will stay for the rest of their lives.
For Azad and Laxmi have a rare hormonal disorder which means that they will forever be trapped in the bodies of five-year-olds – the age she stopped growing because of a congenital defect affecting their pituitary gland which arrested their development.
Laxmi, from Gurgoan, near India's capital New Delhi said: "I've watched all my friends grow into young women and their bodies change.
"I'm not growing on any front. I should be wearing a bra by now but I don't have breasts and I haven't started menstruating. I'll never be able to have children.
"I sometimes think about the normal life I could have had and it makes me sad.
"I've been bullied all my adult life for being small. I rarely go out as I'm scared I will be harmed.
"Once, a child from our community was abducted and taken in a van. I've been terrified ever since. And if I see a van lurking around I run home.
"I fear I'll be sexually attacked, which is rife in India. Being so small I'd be an easy target. So I never go anywhere alone."
Despite their differences, Laxmi and Azad went to the same school as their normal-sized younger sister, Suman, 15.
Despite their challenges, they thrived, getting top marks in her exams. Azad is now at high school studying for the equivalent of her GCSEs.
Laxmi said: "I was lucky to have school friends who never bullied me and often protected me. But when I stepped away from my family or circle of friends people were always nasty.
"I hate meeting new people as it hurts getting stared at and bullied every time. I ve now learnt to ignore them and sometimes I'll be rude and tell them what I think."
But both Laxmi and her brother are desperate to lead a normal life – something which human growth hormone treatment could help with – yet her mum and dad, Parvati and Bahadur, are too poor to pay for it.
Their security guard dad Bahadur, 58, earns 8,000 rupees (£88) a month, nowhere near the £670
needed for the treatment.
Dr Ritesh Gupta, an endocrinologist and assistant director, at Fortis Hospital, New Delhi, told the Sunday People: "Available treatments are much more effective when started at an early stage."
He said the siblings will remain as they are 'unless there is a proper investigation done' and they are treated accordingly.