Tuesday, August 16, 2011

Today we got our referral to endocrinology. Our appointment is next week, on the 24th.

I got a letter from Medical Genetics today, also, going over everything we talked about at our appointment with them.

Physical Examination:
Weight: 3.73kg (2nd-3rd %ile)
Length: 51.5cm (0.1-1st%ile)
Head Circumference: 37cm (15th %ile)

Ellie appeared much more alert and responsive than when I saw her last, many weeks ago in the nursery. She had facial features in keeping with her family, and also with PWS, with bi-temporal narrowing, mild dolichocephaly, narrow palpebral fissures, small mouth, small hands (6.1cm <-2SD), small feet (7.3cm; <<-2SD), and light pigmentation. She had normal cardiac sounds, clear chest, no hepatosplenomegaly, and normal genitalia. Her tone had improved, although head lag and mild slip-through with axillary suspension were still present. The Moro response was present. She had somewhat more than expected cutis marmorata. Her eye movements were conjugate.

Impression and Plan
Ellie has a history and physical features consistent with her molecular diagnosis of Prader-Willi syndrome. I have reviewed the following points with Jason and Susanne:

Ellie has a deletion of chromosome 15q11-13, presumably the paternal chromosome, which is the most common cause of PWS. I explained that this occurs sporadically and there was certainly nothing they could have done to cause it. The chance of recurrence in another child would be 1% or less, and they could choose CVS or amniocentesis in future pregnancies to rule out PWS, if wished for.

PWS reults because there is no expression of a set of genes in that region: not from the paternal chromosome because those genes have been lost, and not from the maternal chromosome, because throse copies are normally silenced, or turned off.

Issues facing an individual with PWS include:
* infantile hypotonia. This can be quite sever sometimes and often accompanied by lethargy and sleepiness, as it was for Ellie. The hypotonia steadily, gradually resolves, although motor milestones are delayed (average age to sit: 12 months; walk: 24 months), and upper body strenght in particular may also remain decreased from normal into adulthood. Individuals with PWS have decreased muscle mass.
*Hyperphagia [she wrote a bunch, but it's not relevant at the time being]
*Growth hormone deficiency. Many children have growth hormone deficiency, which causes not only short stature but also contributes to decreased muscle mass and and abnormal fat distribution. Treatment of children with deficiency ameliorates these finding, and interestingly also has effects on other physical features, such as facial featyres becoming more similar to parents, and hands and feet growing to a normal size. I am putting through a referral to Endocrinology for consideration of whether this would be appropriate or not, a discussion of risks and benefits, and review of the issues of coverage in BC. I am also requesting that they consider testing for cortisol deficiency, which affects a minority of children, and suggest a schedule for TSH testing, which affect 15% at some point.



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