Understanding neurofibromatosis, a relatively unknown genetic disorder
KUALA LUMPUR: Dr Nurul Izzaty Hassan had a relatively problem-free pregnancy when she was expecting her youngest daughter Abeer Jannah Ahmad Ezhan three years ago.
When she was 26 weeks pregnant, a 4D ultrasound scan was conducted. Even though the sonographer noted her baby’s head was somewhat larger than average, it was still within an acceptable range, so there was no need for concern.
“Because it was closer to my home, I chose to give birth at a private hospital in Bangi (in Selangor) due to the resurgence of Covid-19 cases in early 2021.
“Abeer Jannah was born at 39 weeks and it was a vacuumassisted delivery due to her slower heartbeat,” Nurul Izzaty, 40, an associate professor of organic chemistry at the Faculty of Science and Technology, Universiti Kebangsaan Malaysia, told Bernama.
She said after the delivery, the obstetrician/gynaecologist called a paediatrician to examine the baby because her right eye was swollen.
“I was stunned by the situation and tried hard to figure out what was wrong. The ob-gyn suspected a retinoblastoma or eye cancer, and started asking me whether my family had a history of such a condition,” she said.
On the second day, the paediatrician explained to Nurul Izzaty the possibility of her baby being diagnosed with neurofibromatosis type 1 (NF1) due to the presence of multiple ‘café-au lait’ spots (brown patches) on her body.
The baby was transferred to Hospital Tunku Azizah (formerly known as Women and Children’s Hospital, Kuala Lumpur) the following day and within two weeks, an MRI (magnetic resonance imaging) of her brain confirmed the presence of plexiform neurofibromas in her right brain.
“In this instance, we had an immediate diagnosis of NF1,” said Nurul Izzaty.
Symptoms of NF1
Neurofibromatosis (NF) is a multisystem genetic disorder that is characterised by the development of tumours on nerve tissue, skin pigmentation changes and other potential complications affecting various systems in the body.
According to Prof Dr Thong Meow Keong, a consultant clinical geneticist at the University of Malaya Medical Centre and Dean of the M. Kandiah Faculty of Medicine and Health Sciences, Universiti Tunku Abdul Rahman, NF refers to three different conditions – NF1, NF2 and schwannomatosis – involving the development of tumours that may affect the brain and spinal cord as well as the nerves that send signals between the brain and spinal cord and other parts of the body.
“Most of the tumours are noncancerous (benign) although some may become cancerous (malignant),” he said.
NF1 is also known as von Recklinghausen disease, and one in 3,000 children is estimated to be diagnosed with it globally. NF1 is usually diagnosed during childhood. NF2 and schwannomatosis (SWN) are rarer conditions.
“NF1 is a genetic autosomal dominant disease with a 50:50 split, either inherited from the parents or caused by spontaneous mutation at the NF1 gene.
“The gene controls the production of a protein called neurofibromin (neurofibromin 1). This gene is believed to function as a tumour suppressor gene. In about 50 percent of people with NF1, the disorder results from gene variants that occur for unknown reasons (spontaneous mutation),” explained Dr Thong.
He said the most common symptoms of NF1 are brownish spots on the skin, bumps on and under the skin (called neurofibromas), a head that looks large for the body, headaches, learning difficulties, attention problems, hyperactivity, shorter stature compared to most children of the same age, curves in the backbone (scoliosis) and changes in the irises with an increased risk of developing optic pathway glioma (a form of brain tumour involving the optic nerve) at a later stage of their lives.
“As the early symptoms can be variable and include light brown spots (‘café au-lait’ macules) on the skin or bumps that develop either on or under the skin, with risk of developing optic glioma at a later stage of their lives, it can be challenging for parents to identify the onset of the disease in their child,” he added.
He said about 30 to 50 per cent of patients with NF1 may experience plexiform neurofibromas (PNs), the majority of which are present at birth. PNs are tumours that grow along nerves. The tumours are benign but can turn into cancer.
“PNs can cause extreme disfigurement, be very disabling and interfere greatly with regular growth and functioning.
“NF1 also often carries a significant psychosocial burden for patients as other symptoms include tumours that grow on the nerves, causing visible bumps on the extremities (hands and feet) and face that may draw unwanted attention in public,” he added.
How is NF1 diagnosed?
NF1 can be diagnosed with careful history-taking which may include detailed medical and family history, a thorough physical examination followed by an ophthalmological examination using a slit lamp for eye changes such as Lisch nodules and optic glioma.
Dr Thong said doctors may order a brain and spinal cord MRI scan, which uses a powerful magnetic field and radio waves to produce detailed pictures of the brain and spinal cord, to look for changes and tumours.
Genetic counselling followed by genetic testing for NF1 and NF2 are available in tertiary centres with genetic services, he added.
Commenting on the connection of NF1 with cancer, he said as NF genes are tumour suppressor genes, any change in them will result in abnormalities in the growth of the nerve cells.
“In NF1, the tumours occur in the small nerves of the skin and the large nerves inside the body; in NF2, tumours primarily affect the auditory nerves that connect the ears to the brain and control hearing.
“NF2 patients can also develop tumours in the nerves of their body”, he added.
Lifetime risks of both benign and malignant tumours increase in individuals with NF1. However, if there are no complications, the life expectancy of people with NF is almost normal in most cases.
Dr Thong said the long-term care for persons with NF1 aims at early detection and treatment of complications as they occur, with a multidisciplinary team usually involved in this. Longterm care includes tumour surveillance and monitoring of blood pressure and treatment of bone and neurological complications.
“Genetic counselling, psychological support and the various reproductive health options for parents are provided. Patient support groups also play an important role,” he added.
Challenges of NF1
Meanwhile, sharing her experience, Nurul Izzaty said caring for a child with a medical condition like NF1 presents various challenges for parents as it includes managing their children’s medical needs and going for genetic counselling.
“We have to be able to coordinate and manage medical appointments with various specialists and although in Abeer’s case, it is a ‘de novo’ mutation (none of the family members are carriers), we are impacted by the emotional aspects of having such a genetic condition within the family, which led us to consider genetic counselling for family planning.
“And, since NF1 is a genetic condition, no insurance is available to manage the healthcare cost of our child’s ongoing medical needs. In terms of emotional and social aspects, Abeer’s face has been disfigured with severe scoliosis due to the extensive size of the plexiform neurofibromas.
“These visible physical differences may create a stigma later in her life,” she said, adding she takes her daughter for regular medical check-ups to monitor her growth as well as look out for any symptom of NF1-related complications.
The mother-of-two said an MRI is carried out yearly to check the size of Abeer’s PNs. The child also undergoes regular eye examinations and has to go to the following three hospitals for specific treatments: Hospital Pakar Kanak-Kanak UKM Cheras, Hospital Tunku Azizah and University of Malaya Medical Centre. Abeer also has to attend physiotherapy, and speech and occupational therapy every two weeks.
“Every situation is unique and individual experiences vary. The first six months impacted my emotional well-being as I had to deal with the uncertainty, fear and sadness in coping with her diagnosis while coordinating appointments with various specialists and understanding complex medical information.
“After a year, I struggled to balance my responsibilities at work and with my family and personal commitments. I felt I had lost myself. I was depressed,” Nurul Izzaty said.
However, after connecting with other parents facing similar challenges, she managed to change her ways of dealing with stress and anxiety and is now able to cope better with the challenges of raising her child.
Nurul Izzaty also called for public awareness campaigns to help educate society about NF1 as well as foster more understanding of the condition and reduce stigma.
She said media platforms can be used to raise awareness about NF1 and share stories of resilience.
“We should encourage an inclusive and supportive community environment to help families feel more connected and accepted.
“Sometimes, I encounter difficulties explaining the condition to friends, extended family and the broader community due to the lack of awareness about NF1 which may contribute to misunderstandings and misconceptions,” she said, adding healthcare professionals must also be well-informed about NF1 and its implications.
NF1 is a genetic autosomal dominant disease with a 50:50 split, either inherited from the parents or caused by spontaneous mutation at the NF1 gene.
Prof Dr Thong Meow Keong