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Bohring-Opitz syndrome is characterized by intrauterine growth retardation (IUGR), failure to thrive, facial dysmorphism (prominent metopic suture and forehead nevus flammeus, a low frontal and temporal hairline with hirsutism, puffy cheeks, upslanting palpebral fissures, exophthalmos, hypertelorism, cleft lip and palate, retrognathia and low set ears), flexion deformities of the elbows and wrists, camptodactyly, ulnar deviation of the fingers, foot anomalies and severe developmental delay. Less than 20 patients have been described so far. Although the large majority of reported cases occurred sporadically, autosomal recessive inheritance has also been reported.
Features include always present findings: Profound intellectual disability, Microcephaly, Feeding difficulties, and Proptosis and others; and very common findings: Trigonocephaly, Flexion contracture, Low muscle tone (hypotonia), and Hypertrichosis and others. 100 total HPO annotations.
Organ System | Phenotype Count | Example Features |
|---|---|---|
Head and neck | 9 | Microcephaly, Bilateral cleft palate, Unilateral cleft palate |
Muscles | 8 | Flexion contracture, Low muscle tone (hypotonia), Facial hypotonia |
Brain and nerves | 7 | Seizure, Profound intellectual disability, Global developmental delay |
Digestive system | 5 | Gastroesophageal reflux, Feeding difficulties, Intestinal malrotation |
Arms and legs | 5 | Overlapping toe, Mesomelic/rhizomelic limb shortening, Tapered finger |
Eyes | 4 | Strabismus, Abnormal optic nerve morphology, Damage to the optic nerve (optic atrophy) |
Growth and development | 4 | Short stature, Failure to thrive, Intrauterine growth retardation |
Lungs and breathing | 4 | Neonatal respiratory distress, Apnea, Recurrent respiratory infections |
Heart and blood vessels | 3 | Ventricular septal defect, Atrial septal defect, Bradycardia |
Bones and joints | 2 | Joint dislocation, Limitation of joint mobility |
Blood and immune system | 2 | Recurrent infections, Recurrent respiratory infections |
Pregnancy and birth | 2 | Neonatal respiratory distress, Congenital contracture |
Kidneys and urinary system | 1 | Urinary retention |
Age of onset: newborn period.
Bohring-Opitz syndrome (BOS) is a rare condition characterized by distinctive facial features and posture, variable but usually severe intellectual disability, growth failure, and variable anomalies. Feeding difficulties have a significant impact on overall health in early childhood; feeding tends to improve with age. This section summarizes clinical data from numerous case reports and case series; see and references therein, , and Suggested Reading. Additional references are cited where appropriate. Craniofacial. Individuals with BOS have a characteristic facial appearance , although significant variability is observed.
Source: GeneReviews — "Bohring-Opitz Syndrome"
ASXL1 encodes ASXL transcriptional regulator 1 (1,541 aa). Probable Polycomb group (PcG) protein involved in transcriptional regulation mediated by ligand-bound nuclear hormone receptors, such as retinoic acid receptors (RARs) and peroxisome proliferator-activated receptor gamma (PPARG). Highest expression in Nerve Tibial (62.7 TPM) and Testis (61.1 TPM).
Bohring-Opitz syndrome is caused by mutations in the ASXL1 gene on chromosome 20.
The ASXL1 protein participates in Keratinocyte stem cell differentiates into transit amplifying cell in the basal layer of interfollicular epidermis pathway.
ASXL1 is classified as a druggable target (Clinically Actionable and Nuclear Hormone Receptor categories) with score 0.0.
Prior to the identification of the molecular cause of Bohring-Opitz syndrome (BOS), had proposed clinical diagnostic criteria for the condition. Ultimately, only five individuals used to develop these clinical diagnostic criteria were molecularly confirmed to have BOS. Therefore, the specificity of these diagnostic criteria is unclear.
Bohring-Opitz syndrome should be suspected in individuals with the following clinical features [, , , , ]. Craniofacial appearance
Microcephaly or trigonocephaly / prominent (but not necessarily fused) metopic ridge
Glabellar and eyelid nevus flammeus (simplex) that fades with age
Prominent globes
Cleft lip
Palatal anomalies: cleft palate, high arched palate, or prominent palatine ridges
Micrognathia and/or retrognathia
Growth and feeding
Source: GeneReviews — "Bohring-Opitz Syndrome"
Table 2.
Disorders to Consider in the Differential Diagnosis of Bohring-Opitz Syndrome (BOS)
Disorder | Gene(s) | MOI | Clinical Features of Differential Diagnosis Disorder
Overlapping w/BOS | Distinguishing from BOS
C syndrome (Opitz trigonocephaly syndrome)1(OMIM 211750) | CD96 | AD | • Severe DD/ID
Microcephaly
Trigonocephaly
Upslanting palpebral fissures
Retrognathia
Low-set ears
| Common in BOS, not in C syndrome:
Nevus flammeus (simplex) over glabella
BOS posture
Poor linear growth
Feeding difficulties
High myopia
Shashi-Pena syndrome (ASXL2 syndrome)2 | ASXL2 | AD | • DD
Source: GeneReviews — "Bohring-Opitz Syndrome"
Genetic testing for ASXL1 is available. Testing is considered confirmatory for diagnosis.
Biomarker and diagnostic research for Bohring-Opitz syndrome has been reported in the published literature.
No approved treatments are currently available for Bohring-Opitz syndrome. The disease remains an area of unmet medical need.
Evaluations Following Initial Diagnosis To establish the spectrum of manifestations and medical needs in an individual diagnosed with Bohring-Opitz syndrome (BOS), the following evaluations are recommended if they have not already been completed. Table 3. Recommended Evaluations Following Initial Diagnosis of Bohring-Opitz Syndrome
System/Concern | Evaluation | Comment |
|---|---|---|
Growth | Weight, length/height, head circumference measurements plotted on standard growth chart | Goal: normal weight-for-length or body mass index; Expected final adult height: 2nd centile |
ENT/Mouth | Craniofacial evaluation if cleft lip/palate, micrognathia, or obstructive sleep apnea is present | If mainly due to tongue-based airway obstruction, severe obstructive sleep apnea may be treatable by adenoidectomy or mandibular distraction. Gastrointestinal |
Neurologic | Assessment for signs/symptoms of seizures | If present, consider neurology evaluation head MRI. Evaluation by developmental specialists incl speech, occupational, physical therapists |
Cardiovascular | Echocardiogram for cardiac anatomy | — |
Respiratory | Assessment for apnea/bradycardia (more common in younger individuals) | Consider sleep study if sleep apnea is a concern. |
Eyes | Ophthalmology evaluation | For high myopia retinal/optic nerve defects |
Genitourinary | Baseline renal ultrasound | To assess renal structure screen for Wilms tumor |
Musculoskeletal | Orthopedic evaluation if bony anomalies noted | Miscellaneous/ |
Other | Consultation w/clinical geneticist /or genetic counselor | Treatment of Manifestations Table 4. |
Treatment of Manifestations in Individuals with BOS Manifestation/Concern | Treatment | Considerations/Other |
Frequent infections /or aspiration pneumonia4 | Aggressive management of chronic emesis | Fever or increase in emesis |
Seizures | Standard antiepileptic medications | Most individuals respond to monotherapy. |
Congenital heart defects | Standard management | Respiratory symptoms |
Sleep disturbances | Melatonin, treatment of anemia | — |
Myopia | Corrective lenses, often first prescribed in infancy | — |
Urinary retention, urinary tract infections, kidney stones | Standard treatments | Appropriate management of these conditions can improve emesis hospitalization rate. |
Source: GeneReviews — "Bohring-Opitz Syndrome"
2 trials found
The following are appropriate:
Renal ultrasound every three months from birth to age eight years to screen for the development of Wilms tumor
Frequent monitoring of growth and development with interventions as needed
Close management of feeding intolerance with a gastroenterology specialist
Regular follow up with an ophthalmologist for vision optimization
Source: GeneReviews — "Bohring-Opitz Syndrome"
Phenotype severity distribution: 5 always present features, 8 very common features, 40 common features.
Estimated prevalence: <1 in 1,000,000 (VERY_RARE).
2 clinical trials registered, 2 recruiting. Interventions under study include other interventions. Research is primarily sponsored by academic and government institutions.
9 publications have been identified in PubMed for Bohring-Opitz syndrome. Research spans Case Report / Case Series (44%), Basic Science / Preclinical (22%), and Diagnostic / Biomarker (11%).
Piring A (2026). [PMID: 40808361](https://pubmed.ncbi.nlm.nih.gov/40808361/). *American journal of medical genetics. Part A*. [Epidemiology / Natural History]
Fernández-Hernández L (2026). [PMID: 41751615](https://pubmed.ncbi.nlm.nih.gov/41751615/). *Genes*. [Case Report / Case Series]
Kim H (2025). [PMID: 40276524](https://pubmed.ncbi.nlm.nih.gov/40276524/). *Animal cells and systems*. [Basic Science / Preclinical]
Fu MP (2025). [PMID: 40742536](https://pubmed.ncbi.nlm.nih.gov/40742536/). *The Journal of experimental medicine*. [Case Report / Case Series]
Lin CM (2024). [PMID: 39098553](https://pubmed.ncbi.nlm.nih.gov/39098553/). *Pediatrics and neonatology*. [Diagnostic / Biomarker]
Lin I (2024). [PMID: 39614348](https://pubmed.ncbi.nlm.nih.gov/39614348/). *BMC medical genomics*. [Basic Science / Preclinical]
Thambar S (2024). [PMID: 39503249](https://pubmed.ncbi.nlm.nih.gov/39503249/). *Orthodontics & craniofacial research*. [Clinical Trial Publication]
Arioka M (2024). [PMID: 39423952](https://pubmed.ncbi.nlm.nih.gov/39423952/). *European journal of medical genetics*. [Case Report / Case Series]
Patel K (2024). [PMID: 38637906](https://pubmed.ncbi.nlm.nih.gov/38637906/). *Pediatric blood & cancer*. [Case Report / Case Series]
Data assembled from 9 of 12 sources · Last updated Sep 20, 2026, 3:02 PM UTC
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AI-curated news mentioning Bohring-Opitz syndrome
Updated Jul 21, 2026
FDA approved Casgevy CRISPR gene therapy for children as young as 2 with sickle cell disease on July 1, 2026. Here's what families need to know about this milestone. Approximately 5,500 additional American children are now eligible for this established one-time therapy, according to Vertex Pharmaceuticals, Casgevy's developer. Casgevy also covers transfusion-dependent beta-thalassemia in this new age indication. Sickle cell disease is a lifelong inherited blood disorder that warps red blood cells into stiff, crescent shapes that can block blood flow, starving organs and tissues of oxygen. The world's first CRISPR-based gene therapy has been approved for children as young as two years old, opening the possibility of a single, potentially curative treatment to thousands of American children with sickle cell disease before years of organ damage can narrow what medicine can do for them. Families with children aged 2 and older who have sickle cell disease should speak with their pediatric hematologist about whether Casgevy is appropriate to consider at this stage of their child's disease. Ask specifically which authorized treatment centers perform Casgevy in your region. Treatment is available only at specialized sites, and geographic access remains limited. Contact your child's insurance plan or Medicaid office to ask about coverage. Medicaid coverage for gene therapies varies by state, and some states have developed outcomes-based payment models for high-cost therapies. "With today's decision, pediatric patients as young as 2 years of age can now access a critical additional treatment option to treat these debilitating, life-threatening diseases," said Karim Mikhail, acting director of the Office of Therapeutic Products at the FDA's Center for Biologics Evaluation and Research, according to the FDA press announcement. Casgevy is a non-viral, ex vivo CRISPR/Cas9 gene-edited cell therapy.
A new treatment for children aged 2 or older with sickle cell disease has been approved by the U.S. Food & Drug Administration. In a press release on Wednesday, the FDA announced it had approved Casgevy, the first gene therapy for children with sickle cell disease. (NewsNation) — A new treatment for children aged 2 or older with sickle cell disease has been approved by the Food & Drug Administration (FDA). In a Wednesday news release, the FDA announced it had approved Casgevy, the first gene therapy for children with the disease. “Casgevy is a gene therapy consisting of the patient’s own (autologous) hematopoietic (blood) stem cells, administered as a one-time single dose for intravenous infusion,” the release noted. “Pediatric patients as young as 2 years of age can now access a critical additional treatment option to treat these debilitating, life-threatening diseases,” Karim Mikhail, the acting director of the Center for Biologics Evaluation and Research, wrote. “These disorders carry a heavy burden for children and their families, affecting growth, development, and long-term health in profound ways,” Megha Kaushal, acting deputy director of the Office of Therapeutic Products in CBER, said in the release.