About ASXL1/Bohring-Opitz Syndrome (BOS)
Overview
About
Bohring-Opitz Syndrome is typically caused by a de novo (new) mutation of the ASXL1 gene. The mutation usually happens randomly and is not inherited from parents. Read more about what causes ASXL-related disorders
The syndrome is named after Axel Bohring and John Opitz, two of the doctors to initially describe cases of Bohring-Opitz Syndrome in the medical literature between 1999 and 2006. Some of the earlier research identifies Bohring-Opitz Syndrome as “Opitz trigonocephaly C” syndrome and “Oberklaid-Danks Syndrome.”
Clinical characteristics
There is significant variability in the severity of symptoms of people who have Bohring-Opitz Syndrome and we don’t yet have a good understanding of why that is.
Some of the most common characteristics include:
Distinct features of the face and head, including a heart-shaped birthmark on the forehead (glabellar nevus flammeus), prominent eyes, and head shape anomalies (microcephaly and/or trigonocephaly)
“BOS posture” where the wrists are turned inward
Feeding difficulties in infancy, including cyclic vomiting that may be extreme and lead to hospitalization
Respiratory infections, particularly in infancy
Seizures
Obstructive sleep apnea
Gross motor delay of varying severity
Intellectual disability of varying severity
Increased risk for developing Wilms tumor, a rare pediatric kidney cancer, and hepatoblastoma, a rare pediatric liver cancer (see tumor screening guidelines below)
Published symptoms and clinical features
The ARRE Foundation cataloged a list of all the symptoms reported in the medical literature about individuals with ASXL1/Bohring-Opitz Syndrome. This map of symptoms across health domains is available in a downloadable PDF and is a helpful document to share with your loved one’s doctors.
It’s important to note that all the symptoms listed here are not present in every individual with Bohring-Opitz Syndrome. This is a wide range of symptoms reported across 63 individuals. The intent of this document is to help you and your loved one’s doctors know what signs and symptoms to watch for.
Prevalence
We don’t know how many people have an accurate diagnosis. We estimate that there are approximately 150-200 people diagnosed in the world. We also believe there are many people living undiagnosed.
Diagnosis
Gene sequencing is required to confirm a diagnosis of Bohring-Opitz Syndrome.
Life expectancy
Not enough research has been conducted to know what the average Bohring-Opitz Syndrome life expectancy could be. As genetic testing becomes more widely accessible, we are learning of more people who have been living undiagnosed with Bohring-Opitz Syndrome for many years. The oldest known individuals with Bohring-Opitz Syndrome are in their thirties. All of the people we are aware of who have Bohring-Opitz Syndrome cannot live independently and require lifelong care. Bohring-Opitz Syndrome is not known to be a degenerative disorder (where function decreases over time).
Experts Bianca Russell, MD (UCLA) and Wen-Hann Tan, BMBS (Boston Children’s Hospital) present an update on Bohring-Opitz Syndrome and answer some of the most commonly asked questions from families (July 2021).
Care management
There are no ASXL-specific therapeutics or treatments to address the underlying cause of Bohring-Opitz Syndrome. The treatment approach typically includes the management of complications through a multidisciplinary team of medical specialists and therapists (speech therapy, physical therapy, occupational therapy, etc.). Interventions may include intensive therapy, surgeries, and medication (i.e. seizure control) as warranted. Clinical guidelines were published by Dr. Bianca Russell and her colleagues in 2015.
Tumor screening (updated May 2024)
Three individuals with BOS have been reported to develop Wilms tumor, a rare pediatric kidney cancer. Additionally, three individuals with BOS developed hepatoblastoma, a rare pediatric liver cancer. These cancers are very rare, but they are curable if they are found early. An abdominal ultrasound every three months from birth to age 8 is recommended to screen for the development of tumors on the kidneys and liver. Discuss with your child’s provider the option of measuring alpha fetoprotein (AFP) via blood test every 3 months through age 5 and/or extending ultrasound screenings after age 8 at a lower frequency.
Read the full updated tumor screening guidelines that were updated in May 2024 or download a printable version (PDF) to share with your child’s medical team.
Care management resources:
Research
There has been limited research on Bohring-Opitz Syndrome and the other two ASXL syndromes (ASXL2/Shashi-Pena Syndrome and ASXL3/Bainbridge-Ropers Syndrome). It’s our mission to change that. We’re funding research grants and we support the ASXL Patient Registry and Biobank.
The two best things you can do to advance research into Bohring-Opitz Syndrome are
Continued reading
The following resources have been approved by our Medical and Scientific Advisors as relevant reading for families looking to learn more about Bohring-Opitz Syndrome:
Informational resources
Bohring-Opitz Syndrome Awareness Day
April 6
Bohring-Opitz Syndrome Awareness Day is April 6. Find facts, sharable graphics, and more on our Awareness Days page.
Family support
Parent support group (Facebook page)
The Bohring-Opitz Syndrome support group was founded in 2011 by Sünne van Gemert-Godbersen and Sheri Bermejo, both parents of children with Bohring-Opitz Syndrome. This grassroots group has grown from just a handful of members in its early days to over 570 members from around the world.
Other organizations and resources
bohring-opitz.org
This is an informational website run by families with research, family stories and a map of families with Bohring-Opitz Syndrome.
Bohring-Opitz Syndrome Foundation
The BOS Foundation provides family support, raises awareness of Bohring-Opitz Syndrome, and offers financial scholarships for families to help pay for things such as adaptive equipment.
Unique Bohring-Opitz Syndrome guide
Unique, an organization that provides information on rare disorders, has a downloadable document about Bohring-Opitz Syndrome.
“Kuluut” documentary
The documentary “Kuluut” follows Coen, who has Bohring-Opitz Syndrome, and his family. The trailer is available online and the full documentary is available on The Disorder Channel (accessible via Roku or Amazon FireTV).
Family stories
Some families have Facebook pages and blogs about their family’s experience with Bohring-Opitz Syndrome. Those include:
Newly diagnosed
Has someone you love just been diagnosed with an ASXL-related disorder?
