Alternate gene names: CTIP1, EVI9, KIAA1809, FLJ10173
Associated syndromes or conditions: none known
Genomic location: 2p16.1
Diagnoses observed in people with changes in the BCL11A gene:
- Autism Spectrum Disorder - Yes
- Intellectual Disability or Developmental Delay - Yes
- Epilepsy or Seizures - No
- Attention Deficit Hyperactivity Disorder - No
- Schizophrenia - No
- Bipolar Disorder - No
- BCL11A: Simons VIP Connect Community Simons VIP Connect Facebook Group for BCL11A Families
Infographic: https://magic.piktochart.com/output/5675273-bcl11a-infographic (share this link with others)
Research Article Summaries: As we learn more from children who have these gene changes, we expect this list of resources and information to grow.
- This gene regulates genes involved in making components of our blood cells called "globins."
Basak et al. (2015) - BCL11A deletions result in fetal hemoglobin persistence and neurodevelopmental alterations
Fetal hemoglobin (abbreviated HbF) is a protein that carries oxygen from a mother to her unborn baby. The BCL11A gene is responsible for limiting the amount of fetal hemoglobin (HbF) produced after birth and for transitioning blood cells to produce adult hemoglobin (HbA) while the individual is developing. It is thought that disruptions in the function of BCL11A can increase HbF levels, and thus provide therapy to patients with disorders affecting oxygen transport in the blood (hemoglobin disorders, such as sickle cell disease or beta-thalassemia) since HbF is a more effective oxygen carrier. Recent studies have also shown that this gene may also be associated with autism spectrum disorder (ASD) and developmental delay (DD). To better understand the impact of genetic changes involving BCL11A, Basak et al. identified three patients who were found to have deletions of the BCL11A gene, not inherited from either parent (de novo). All three patients were found to have ASD, moderate to severe DD, low muscle tone (hypotonia) and differences in their facial features. Two of the patients were found to have small head size (microcephaly), and two patients were found to develop problems with coordination, fine motor skills, hyperactivity and aggression as they got older. All three were found to have significantly increased levels of HbF, as well. Since ASD and DD can be associated with increased risks for other neurodevelopmental disorders, the study team also looked at data from a recent study of schizophrenia and found an increased number of cases with genetic variation in the region of the BCL11A gene. While disrupting the BCL11A gene may be useful in increasing the levels of HbF, this study provides evidence that this gene is also involved in contributing to neurodevelopmental disorders, such as ASD, DD, ADHD and schizophrenia; caution must be taken when targeting this gene as a potential therapy for patients with hemoglobin disorders.
Balci et al. (2015) - Brain malformations in a patient with a deletion 2p16.1: A refinement of the phenotype to BCL11A
Previous studies of 15 patients with microdeletions (small deletions) of the BCL11A gene have identified a set of common features that include intellectual disability (ID), developmental delay (DD), and microcephaly (small head size). Individuals were also found to have differences in their facial features, such as increased distance between eyes (telecanthus), small openings of the eyelids (short palpebral fissures), broad nasal roots (top of the nose), flat and elongated philtrums (groove between nose and top lip) and large ears. This article presents a case study of a 3-year-old patient diagnosed with developmental delay and differences in facial features (prominent forehead, wide set eyes, an indented nasal bridge, a small mouth and chin and a thin upper lip). Magnetic resonance imaging (MRI) showed differences in the growth of the brain between patients. Genetic testing by microarray (also known as array CGH or comparative genomic hybridization) identified a deletion of the 2p16.1 region that includes the BCL11A gene. This deletion was not found in either parent (de novo). This articles shows that in addition to being associated with ID, DD and autism spectrum disorder (ASD), BCL11A may contribute to differences in the growth and development of the brain, including underdevelopment of a number of brain structures, such as the corpus callosum (the structure that connects the two halves of the brain) and the cortical gyri (the pattern of how the brain structure is folded).
Peter et al. (2014) - De novo microdeletion of is associated with severe speech sound disorder
Work by previous researchers has shown that deletions of the chromosome region 2p15p16.1, which includes the BCL11A gene, among others, lead to features such as poor growth/short stature, differences in facial and skeletal features, small head size (microcephaly), optic nerve (vision) impairment, low muscle tone (hypotonia), kidney problems, intellectual disability (ID), autistic behaviors, speech and language problems and attention deficit disorder (ADD). This article reports on a case where only the BCL11A gene is deleted and may give clues about which features are specifically associated with this gene. This patient’s deletion of BCL11A was found to be de novo (not inherited from either parent). Like the other reported cases, he had a history of low muscle tone (hypotonia), however, his ID was milder compared with many of the others. He also did not have differences in facial and skeletal features or problems with growth. His verbal abilities were better that the other subjects, although he was reported to have difficulty with articulation and problems with controlling saliva, chewing and swallowing (dysarthria), which can be caused by low muscle tone. He also had a diagnosis of childhood apraxia of speech (CAS), which is a problem where the brain has trouble making the mouth/lips/tongue move correctly to say sounds and words. Based on this case report, the BCL11A gene may affect the development of speech and language abilities and future research may want to look at the role of BCL11A in early brain development and its subsequent impact on language issues, such as dyslexia.
You can also visit SFARI's website to see information for researchers about this gene. SFARIgene: BCL11A
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