Juvenile Batten disease is difficult to diagnose quickly and accurately, as seen in twin girls with different symptoms of the same disorder.
The case suggests that a referral to a specialist should be made when a patient’s clinical picture does not match their history, or when their signs and symptoms point to multiple diagnoses.
The study “Juvenile Batten disease, a diagnostic conundrumWas published in the Journal of the American Academy of PAs.
Fraternal twins – meaning two eggs were fertilized simultaneously – were conceived by in vitro fertilization (IVF) and showed normal results when screening as a newborn.
At the age of 9 months, however, doctors noticed a heart murmur in one of the twins and referred her to a pediatric cardiologist. An echocardiogram revealed a narrow pulmonary valve connecting the heart to the arteries leading to the lungs, and a small opening between the upper chambers of the heart, known as the patent foramen ovale.
Although both daughters had reached all developmental milestones by the age of 12 months, the twin with the heart defects had started to fall behind by 18 months. She presented with delayed speech, abnormal gait and hypersensitivity to sounds. She was diagnosed with autism spectrum disorder at the age of 2, after genetic testing ruled out fragile X and Rett syndromes.
This girl also had academic and behavioral difficulties, including bouts of violence.
While in the first grade, she began to have difficulty seeing the classroom board. Initial eye tests reported 20/20 vision, but was changed to 20/200 in the right eye and 20/300 in the left eye, following an electroretinography test at a hospital for children. The legal blindness threshold is 20/200.
A retinal specialist has discovered macular dystrophy, a relatively rare disease in which the area of ââthe eye with the highest concentration of photosensitive cells deteriorates. The girl was referred to a genetic counselor, who ordered a genetic test.
While awaiting the results of genetic tests, the family discovered that the girl’s twin sister, who had shown no vision problems at this point, could not see the words written in a book with yellow writing on a page. red, indicating color blindness.
The first sister’s genetic test revealed a diagnosis of Batten disease, also known as neuronal ceroid lipofuscinosis, or NCL. A genetic test, which also confirmed Batten’s disease, was ordered for the second sister, due to the hereditary pattern of the disease and the single episode of color blindness.
Symptoms of the rare disease vary widely and often involve loss of vision. It usually starts with loss of central vision and extends to include peripheral vision.
Genetic defects in any of the 14 genes – CLN1 through CLN14 – Batten cause, making a genetic test the gold standard for diagnosis. Genetic testing, however, remains expensive, can take months, and not all Batten disease mutations are known. New ones continue to be discovered.
The twins are now 11 years old and attend public school with the help of an assistant.
Their symptoms include delusions, obsessive-compulsive behavior, mild to moderate dementia, difficulty walking, seizures, and extreme difficulty sleeping. Their medical team includes several specialists and they are prescribed several drugs.
Although children with Batten disease usually appear normal at birth, they begin to miss developmental milestones as they grow older and often show regression. Symptoms develop as the child ages and do not appear together.
âThe diagnosis can be extremely difficult at the onset of the disease,â the report concludes, âbut referral to specialists should be made when the clinical picture does not match the history or when multiple diagnoses are made with the suspicion that all signs and symptoms are part of the underlying and undiagnosed syndrome.