There is a longstanding adage in clinical genetics that states, "If a patient has seen as many specialists as they are years or months old, then it is time to refer them to a genetics clinic".
This unwritten rule illustrates the tendency for clinicians to use genetic testing as a last resort, when other traditional testing approaches have failed to identify the cause of a patient's condition. However, the time spent on traditional testing can lead to missed diagnostic windows and delayed treatment. This diagnostic odyssey can also cause frustration and stress for patients and their families, who are bouncing from appointment to appointment with little to show for it.
At Courtagen, we have found that ordering multi-gene genetic testing panels at the beginning of the diagnostic process can shorten this diagnostic odyssey by months to years, leading to earlier treatment and interventions, and peace of mind for patients and families. Multi-gene panels offer a cost-effective, highly sensitive tool to diagnose patients who may not display the "textbook" features of a disease.
Let's take a look at three cases where genetic testing led to an early diagnose and positive outcomes for the patients.
Case 1: Cardiofaciocutaneous syndrome
A 12-year-old female presented with generalized seizures, status epilepticus, focal seizures, and developmental delay. DNA sequencing revealed a heterozygous pathogenic variant on the MAP2K1 gene consistent with Cardiofaciocutaneous syndrome, a disorder that affects many parts of the body, particularly the heart, facial features, and the skin and hair. People with this condition also have delayed development and intellectual disability.
This diagnosis alerted the physician to the possibility of cardiac structural defects and provided recurrence risk information.
Case 2: Cerebrotendinous Xanthomatosis
A 16-year-old female presented with facial hypotonia with associated speech difficulties, muscle weakness, easy
fatigability with cramping, fine hand tremor, cataracts, chronic daily headaches, hot flashes/excessive sweating, urinary urgency, and a history of alternating constipation and diarrhea. She had a normal brain and spine MRI and spectroscopy. Her brother also had developmental delay, diarrhea, weak facial muscles, speech/language delays, and hearing problems.
DNA sequencing found a homozygous pathogenic variant in the CYP27A1 gene, consistent with Cerebrotendinous Xanthomatosis, a fat (lipid) storage disorder that affects many areas of the body. People with this disorder cannot effectively break down certain lipids, causing fats to accumulate in various areas of the body.
Additional testing revealed two siblings who carried the same mutation. One of the siblings was an infant who can receive preventative therapies. The three siblings are also able to make reproductive decisions based upon this knowledge.
Case 3: Angelman syndrome
A two-year old male presented with generalized seizures, possible epileptic encephalopathy, developmental delay, GERD, protein induced enteropathy, severe allergies, and insomnia.
DNA sequencing revealed a heterozygous predicted pathogenic frameshift variant in the UBE3A gene consistent with Angelman syndrome, a genetic disorder that primarily affects the nervous system. Patients with this disorder typically have delayed development, intellectual disability, severe speech impairment, and problems with movement and balance.
This knowledge helped inform physicians against overmedicating and to use caution with neuroleptic drugs.
To learn more about the multi-gene panels offered by Courtagen, please visit the Genetic Testing page on our website.