This Friday, ABC’s 20/20 will do an update on Sierra and Sienna and there are always a lot of comments that accompany an article or media coverage about them. Some comments are nice and others are not. So, I thought I’d answer a few of the common questions before it airs.
Q: What about the Roloff twins?
A: Yes, the Roloff twins are twins where one is a Dwarf; however, Sierra and Sienna are twins where one is a Primordial Dwarf. So, we’re talking about different forms of Dwarfism.
Q: How is Primordial Dwarfism (PD) different from other forms of Dwarfism?
A: Little is know about Primordial Dwarfism compared to other forms. It is a very rare form of Dwarfism. It is estimated that there are between 100 – 200 PDs in the entire world. What we do know is that each form of Primordial Dwarfism seems to have its own characteristics and its own medical concerns. PDs are also different from other forms in that they’re proportionate similarly to that of an average height person–they’re just smaller.
Q: What form of Primordial Dwarfism does Sienna have?
A: She doesn’t fit into any of the currently identified forms of Primordial Dwarfism. Doctors believe she, among other PDs, have a yet unidentified form. DNA research is currently being done to identify her form of Primordial Dwarfism.
Q: Why doesn’t Sienna look like a Primordial Dwarf?
A: Primordial Dwarfism is such a complex form of dwarfism. While some people with PD have similar features, there are several that do not. Sienna is one of the taller PDs, but there are others who are taller than she is. A few other things in Sienna’s life are attributed to being why Sienna looks/sounds the way she does. For instance, many PDs have very high-pitched voices. Sienna was on Oxygen for over a year. This could be the reason why her voice is lower. Also, she broke her nose when she was about 3 years old. This could be a reason why her nose looks different from other PDs.
Q: Were she and her twin a result of fertility treatments?
Q: How can a dwarf have an identical twin?
A: “Identical” is a misleading term. The more accurate word is “monozygotic”. This means that one egg was fertilized and then split. The timing of when the egg splits can determine just how similar or different twins are. Here’s what Wikipedia says:
Despite being genetically very similar, monozygotic twins are not genetically exactly the same. A study of 92 pairs of monozygotic twins, carried out in November 2012, provided evidence that monozygotic twins acquire hundreds of genetic differences very early in fetal development, due to mutations (or copy errors) taking place in the DNA of each twin after the splitting of the embryo. It is estimated that, on average, a set of monozygotic twins will have about 360 genetic differences that occurred very early in fetal development. These genetic differences that occur very early in fetal development will be present in nearly every cell in the body. Genetic differences due to mutations can also occur later in life, but those that occur at a later stage will be present in a much smaller proportion of body cells.
Primordial Dwarfism is a genetic mutation. This mutation isn’t 100% understood either; this is why doctors and scientists are still looking for answers.
I hope this helps clear up some of the common confusions. 🙂
I also hope you enjoy the show on Friday and see it for what it’s meant to be–a celebration of Sienna knowing that she’s different, but not letting that stop her from having big dreams.