development concerns

[BJmom]

I have 2 children- a 2 yo boy and a 9 mo girl- who I am concerned about.  I know she is still young, but I have some concerns about her development and don't know if these behaviors are normal or not, since it's very different from my son.  I have been reading online and am worried about Rett's syndrome. She is overall very quiet, with some limited babbling.  She doesn't wave, clap or point yet. She seems to have very little receptive language ( things like Where's the ball?).  She doesn't imitate at all- not sounds, facial expressions, actions.  There are times that she shakeswiggles/moves her extremeties (not flapping), but more of every part wiggling at once- hard to explain.  She also breathes through her mouth pretty often- it almost sounds like a puppy panting (I though babies by nature only breathed through their noses.).  She also does some odd things with her hands.  She'll randomly raise her arm up as if waving (but doesn't know how to wave) or put her fingers in the peace sign position, or have her index finger half bent, or point it (but she's not really pointing at something.)  When she picks something up, she rarely uses all 4 fingers- there's always one or two still extended while she's holding something, which makes her constantly drop things.
On the other hand, she is very social- looks when you call her name, makes eye contact/smiles/seems to have joint attention.  She can hold her bottle/sippy, self feed with the pincer grasp, play with and reach for toys.  She can sit up, just started crawling and can stand holding on to something.
The one doctor we saw said it couldn't be Rett's because her head size is still normal, she can sit up, and the signs wouldn't appear until 18 months- but from what I've been reading this isn't necessarily true. And we're not seeing a developmental pediatrician for another 6 months- and that's a long time for me to worry!
If you can offer any insight, I'd really appreciate it- Thanks!

[Lisa Kessler, MS, CGC]

It can be extremely stressful when you have concerns about your child’s development, and you have a 6 month wait to see a specialist.  You mentioned that you are worried about Rett syndrome.  There is genetic testing available for this condition, and there are also several diagnostic criteria that must be met in order for someone to be diagnosed with Rett syndrome.  As you may have read some of the criteria for this condition include normal prenatal history, normal head size at birth and with slower head growth in most individuals after birth, normal psychomotor development for the first 6 months of life, loss of purposeful hand skills between 6 months and 2 and half years, becoming less social, problems communicating, loss of speech, and cognitive disabilities.  I am sorry that I can not offer insight about your daughter’s development.  However, your daughter may benefit from an appointment with a pediatric clinical geneticist who can perform an exam and/or order tests looking for possible causes of developmental delay and evaluate her for Rett syndrome.   You can find a geneticist through the American College of Medical Genetics.  Best wishes to you and your family.