Rare Disease Day: Mom Makes App to Manage PKU

When Sarah Chamberlin left NYU Hospital after the birth of her second child in August 2013, tucked into the folder with her discharge papers was a pink carbon slip of paper with a serial number on it. Another copy of that slip was sent to the newborn screen lab of NY state along with a few drops of her daughter Isabel's blood on a piece of cardstock.

Three days later, when Isabel was five days old, Chamberlin's husband, Adam Bradford, answered a call from Mt. Sinai Hospital. Isabel had tested positive for a rare metabolic disorder, Phenylketonuria, or PKU, and needed to be seen first thing the next morning for further testing.  What followed was a time of intense education, and some grief, as they learned what it would take to keep Isabel healthy in the face of this disorder.  

It led Chamberlin to found HowMuchphe.org an online diet-management tool for people with PKU.

There are two major types of tech products for health: EMRs, or electronic medical records, primarily used by hospitals and physicians, and personal health trackers - like Fit Bit - which help individuals keep track of their own intake and progress.

This is a story about a technological solution that bridges the gap between these two: HowMuchPhe.org, a small-scale web application that is changing the lives of people with PKU.

Today is Rare Disease Day, which recognizes the more than 7,000 diseases that affect fewer than 200,000 people. Some you've heard of - Hemophilia, Muscular Dystrophy - but others are more obscure: only 250 babies born in the U.S. each year are diagnosed with PKU.

People with PKU can't break down the amino acid phenylalanine (phe) which is present in all foods with even the smallest bit of protein. Too much phe in the system can cause irreversible brain damage and other serious symptoms. Those with PKU live on a protein-restricted diet (often only a few grams per day) and get the rest of their nutrition and "safe" protein from a medical formula. This is a lifelong diet.  

In 1981, Virginia Schuett, a nutritionist and the editor of National PKU News, published the first edition of the Low Protein Food List for PKU, an exhaustive catalog of the phe amounts in common foods. Armed with this book, generations of PKU patients dutifully looked up, tallied, and wrote down the phe they consumed each day, working hard to stay within the limits imposed by their doctors.

By the time Sarah Chamberlin's daughter was born in 2013 and diagnosed with PKU, the book was in its 4th edition.  An entrepreneur with her own web development firm, Chamberlin quickly realized that the work of managing the PKU diet could be made much easier through a web app. Chamberlin contacted Virginia Schuett, and with her support and a collaboration with National PKU News Board member Jeb Haber, HowMuchPhe.org was born.

On HowMuchPhe.org, PKU patients (or their parents) create a profile and specify their phe or protein limits for the day, calorie goals, and favorite foods. They can search the database of 7000+ foods that are suitable for the PKU diet, calculate phe based on serving size, weight, or phe amount, and click a button to record the amount eaten to the food log. Users can easily export their food logs to share with their clinicians, who compare phe intake to the levels of phe in their blood at regular intervals. Diets can then be easily adjusted to ensure phe levels remain in range.

Donna Larkin, mother of a teenage boy, says "HowMuchPhe.org is such a wonderful resource. We couldn't function without the database with all its different foods and their phe content. I can't imagine going to back to calculating phe and calories by hand."

It's not just the patients and their families who benefit. National PKU News has been able to use the data developed by the app to analyze what foods PKU patients are eating, and has performed amino acid analysis on the most popular to ensure the values are accurate. The app is also regularly updated as new products come onto the market. Among clinicians, who almost universally prefer electronic records, 75% still report receiving handwritten records from some of their patients. National PKU News is working on an outreach program to clinics to help encourage their patients to use HowMuchPhe.org.

In addition to making life easier for PKU patients and their caregivers, HowMuchPhe.org provides a motivational incentive, similar to apps like Breeze:

Lindsay Dennis, an adult with PKU, says "Although I've been on diet my whole life, my levels have always been high - I've been on a mission to get my levels low for the first time with food documentation and measurement, more blood draws and increase formula.  HowMuchPhe has been a game changer! My levels went from 12.8 at the end of January to 4.9 two weeks later with the help of the site! THANK YOU! These are the lowest levels I've ever seen!"

Amanda Coburn, a Canadian PKU Advocate, says that having the ability to track her progress on graphs "help put things in perspective and let me see my achievements," an important part of staying on diet.

For Chamberlin, who has made the transition from web developer to Executive Director of National PKU News, having the opportunity to apply her years of technical experience to this problem has been very rewarding: "I feel incredibly lucky that I had the skills to make a difference in Isabel's life and the lives of those like her."