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MBD5-associated neurodevelopmental disorder
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Condition

MBD5-associated neurodevelopmental disorder

MBD5-associated neurodevelopmental disorder (MAND) is a rare genetic condition that significantly impacts neurological and physical development, causing intellectual disability, developmental delays, and epilepsy.

Overview

MBD5-associated neurodevelopmental disorder (MAND) is a condition that affects physical and neurological development. Children with MAND typically experience mild to severe intellectual disability and developmental delays. Motor coordination is often poor, and affected children usually do not walk until 2 or 3 years of age, often exhibiting an unbalanced, wide-based gait. Language skills, including both speech production and comprehension, are highly limited.

By age 2, most children with MAND develop recurring seizures (epilepsy). Weak muscle tone (hypotonia) frequently causes feeding difficulties in infancy, and constipation is also common. Sleep disturbances are highly prevalent, including night terrors, frequent nighttime waking, and early morning waking, which often leads to extreme daytime fatigue. Most individuals with MAND display features of autism spectrum disorder, such as a short attention span, repetitive hand movements (stereotypies) like clapping, hand licking, and hand sucking, and teeth grinding.

Physical features of MAND can include subtle facial abnormalities and mild skeletal issues. Rarely, individuals with this condition may also have congenital heart abnormalities.

Symptoms

The signs and symptoms of MAND affect multiple systems of the body and include:

  • Mild to severe intellectual disability and developmental delay
  • Poor coordination and delayed walking with an unbalanced, wide-based gait
  • Severely limited speech production and comprehension
  • Seizures (epilepsy), typically developing by age 2
  • Feeding difficulties due to weak muscle tone (hypotonia)
  • Chronic constipation
  • Sleep problems, including night terrors, frequent waking, and daytime fatigue
  • Autism spectrum disorder features, short attention span, and repetitive hand movements (stereotypies)
  • Teeth grinding
  • Subtle facial features, including thick and highly arched eyebrows, outer ear abnormalities, downturned corners of the mouth, an outward-pointing upper lip (tented lip), and a full lower lip
  • Mild skeletal abnormalities, such as small hands and feet, short fingers and toes (brachydactyly), curved pinky fingers (fifth-finger clinodactyly), or a wide gap between the first and second toes (sandal gap)
  • Rarely, heart abnormalities

Frequency

MAND is considered a rare disorder, though its exact prevalence is unknown. More than 100 affected individuals have been documented in scientific literature.

Causes

MAND is most commonly caused by a loss (deletion) or gain (duplication) of genetic material on chromosome 2 in a region designated as 2q23.1. These chromosomal changes are referred to as 2q23.1 microdeletions or 2q23.1 microduplications. While the size of the missing or extra genetic material varies, it always includes the MBD5 gene. Less frequently, MAND is caused by mutations occurring solely within the MBD5 gene itself. Researchers believe that alterations in this gene are responsible for the primary signs and symptoms of the condition.

The MBD5 gene provides instructions for producing a protein that regulates gene expression, controlling proteins involved in neurological functions like learning, memory, and behavior. The MBD5 protein also plays a role in cell growth, division (proliferation), and maturation (differentiation).

Genetic changes associated with MAND disrupt the normal levels of MBD5 protein. Mutations and deletions prevent one copy of the gene from producing functional protein, reducing overall levels, while duplications lead to an excess of the protein. Both an increase and a decrease in MBD5 protein levels impair gene regulation, disrupting brain development and behavior. The exact cause of the skeletal abnormalities and other non-neurological features of MAND remains unclear.

Inheritance

MAND is considered an autosomal dominant condition because an alteration in a single copy of chromosome 2 or the MBD5 gene in each cell is sufficient to cause the disorder. Most cases are de novo, occurring as random events during the formation of reproductive cells (eggs or sperm) in a parent, with no prior family history of the condition. In a small percentage of cases, individuals inherit the genetic alteration from an affected parent.

Other Names for This Condition

  • 2q23.1 microdeletion syndrome
  • 2q23.1 microduplication syndrome
  • MAND
  • MBD5 haploinsufficiency

Frequently Asked Questions

Seizure work‑up for a child with MBD5 should begin with a routine EEG to document abnormal electrical activity. If the EEG is inconclusive, a video‑EEG monitoring session over 24–48 hours can capture typical seizure patterns. Magnetic resonance imaging (MRI) of the brain is recommended to rule out structural lesions, especially if seizures are focal or refractory. Genetic testing confirming a pathogenic MBD5 variant is usually performed early in the diagnostic process; if not yet done, a chromosomal microarray or targeted MBD5 sequencing should be requested. Early confirmation allows the team to tailor anti‑seizure medication choices and anticipate developmental support needs. How can parents manage feeding difficulties caused by hypotonia in infants with MBD5, and what feeding positions or tools are most effective?::Infants with MBD5 often benefit from a high‑calorie, nutrient‑dense diet and thickened liquids to reduce aspiration risk. Positioning is key: feed the baby in a semi‑upright angle (45–60°) and use a small, soft‑tipped bottle or a specialized feeding cup that allows controlled flow. A feeding therapist can teach gentle oral‑motor exercises to strengthen swallowing muscles. If oral feeding remains unsafe, a nasogastric or gastrostomy tube may be considered to ensure adequate nutrition while minimizing choking episodes. What therapies are recommended to improve motor coordination and gait in children with MBD5, and how frequently should they be performed?::Early intervention with physical therapy focusing on strength, balance, and gait training is essential. A typical program includes daily stretching, weight‑bearing exercises, and use of assistive devices such as a walker or orthotic braces to promote a stable, wide‑based gait. Occupational therapy can address fine‑motor skills and adaptive equipment for daily activities. Consistency—ideally 30–45 minutes of targeted therapy 3–5 times per week—yields the best gains, and progress should be reassessed every 3 months to adjust the plan. What strategies can improve sleep quality in children with MBD5, and are there medications that can safely be used?::Behavioral sleep hygiene is the first line: establish a consistent bedtime routine, limit screen time before bed, and create a dark, quiet sleep environment. If sleep disturbances persist, a pediatric sleep specialist may recommend melatonin at low doses (0.5–1 mg) to help regulate circadian rhythms. In cases of severe night terrors or frequent awakenings, short‑acting benzodiazepines (e.g., clonazepam) can be used under strict medical supervision, but the risks of respiratory depression must be weighed. Regular follow‑up is essential to monitor efficacy and side effects.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

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