It Took Doctors 20 Years to Diagnose These 2 Sisters

At long last, a chief of genetics was able to identify the cause of their unique symptoms.

Newborn TwinsJulie Campbell/ShutterstockThe patients: Katie, 26, and Ella, 24, of Boston, United States*

The symptoms: Late-onset speech and motor-skill delay

The doctor: Dr. David Sweetser, chief of medical genetics and metabolism at the Mass General Hospital for Children

When Katie was born in 1988, everything seemed fine. Her mother, Laura, worried that Katie’s baby babble and motor skills weren’t as advanced at seven months as those of some of her friends’ kids, but the pediatrician reassured her. It wasn’t until Laura was pregnant with her second daughter, Ella, that it became clear that something was amiss. (Learn the things your child’s pediatrician won’t tell you.)

Although bright and happy at one and a half, Katie still hadn’t taken her first steps and only said a few words: “Mama,” “Dada,” “dolly,” “bubbles.” The family’s lives became a blur of trips to various therapists. Laura had undergone an amniocentesis in her first pregnancy, but nothing unusual had surfaced; Ella was subjected to precise tests in utero to look for chromosomal abnormalities. The results were normal.

Ella’s first 12 months were uneventful, but then she, too, showed signs of developmental delay. As time passed, the gap between the girls’ ages and abilities continued to widen. They were referred to an autism specialist, who diagnosed them with an atypical variant; their social interactions and sustained eye contact set them apart from the standard presentation of the disorder. Here are some things you should never say to parents of children with autism.

Laura quit her job as a professor to devote her time to caring for her daughters—and finding a definitive diagnosis.

At age six, Katie’s speech began to deteriorate. She lost interest in play and withdrew. Laura was terrified.

To her relief, Katie’s condition stabilized within a year. But over the next decade, developmental pediatricians and six geneticists were consulted. Every few months, the girls underwent different exams. Their blood and urine were analyzed; they had muscle and skin biopsies and were tested for a host of conditions.

The results were all negative. The girls struggled with constipation, urinary tract infections, and insomnia. Katie would periodically hyperventilate, while Ella began having seizures at age 13. Otherwise, their symptoms were fairly identical.

In April 2011, when the sisters were in their early 20s, the family met Dr. David Sweetser, the chief geneticist at the Mass General Hospital for Children, where the girls were being treated. “It was daunting to look at their medical sheets,” he says. “It was a decades-long diagnostic odyssey.”

Sweetser tried a new sequencing test that looks at every gene (all 23,000) and discovered a mutation in a single one (TCF4) that plays a crucial role in brain and nervous system development. This glitch causes Pitt-Hopkins syndrome, a disorder discovered in 2007 that’s only been identified in about 350 people worldwide.

At last, the family’s quest for an answer was over. A Pitt-Hopkins diagnosis often comes as a relief, says Sweetser, because it’s typically a random genetic mutation that’s unique to the child and not detected in the parents. (Because Katie and Ella share an identical mutation, one parent also carries the gene in a small subset of egg or sperm cells.)

The best news? Pitt-Hopkins isn’t progressive. Katie and Ella—now in their mid-twenties—are doing well. Their cognitive age ranges from two to five years, depending on the skill area. They love music and playing in the sand on the beach. “They’re happy, friendly young women,” Sweetser says.

After the diagnosis, MGH launched the world’s first Pitt-Hopkins clinic to improve patient quality of life and spearhead research that could lead to targeted therapies. The clinic has created a community for families who have spent years searching for answers. “Just knowing what the defect is can lead to better treatment, and hope for the future,” Sweetser says.

Sweetster isn’t the only super-doc out there. Learn about the doctor who saved a man from a deadly fungal infection.

*Names changed to protect patient privacy

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