What are the signs and symptoms of MECP2 duplication syndrome? MECP2 duplication syndrome is a condition that occurs almost exclusively in males and is characterized by moderate to severe intellectual disability. Infants affected by this condition are generally diagnosed with severe hypotonia within the first few weeks of life. This reduced muscle tone can lead to feeding difficulties which may require a feeding tube. Trouble swallowing, gastroesophageal reflux, failure to thrive, and extensive drooling are also common symptoms. Distinctive physical features may be noticed shortly after birth which can include brachycephaly (abnormally flat back of the head), midface hypoplasia (underdevelopment of the middle of the face), large ears, deep-set eyes, prominent chin, and a depressed nasal bridge. Due to hypotonia, affected children often have delayed development of motor milestones such as sitting up and crawling. Approximately, one third of affected people never walk independently and those who are able to walk may have an abnormal gait (style of walking). In most cases, hypotonia gives way to spasticity during childhood. Progressive spasticity, which is generally more pronounced in the legs, may lead to the development of mild contractures. Consequently, many affected adults require the use of a wheelchair. The majority of affected people do not develop the ability to talk. Some may have limited speech during early childhood, but frequently this ability is progressively lost during adolescence. Other signs and symptoms associated with MECP2 duplication syndrome may include seizures; autistic features; clinically significant constipation and bladder dysfunction. Many people affected by MECP2 duplication syndrome have recurrent respiratory tract infections. These respiratory infections can be life-threatening and as a result, approximately half of affected people succumb by age 25. In most cases, females with a duplication of the MECP2 gene do not have any symptoms, although depression, anxiety, and autistic features have been described in some. When affected, women with MECP2 duplication syndrome are generally less severely affected than males with the condition. The Human Phenotype Ontology provides the following list of signs and symptoms for MECP2 duplication syndrome. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Abnormality of metabolism/homeostasis - Abnormality of the teeth - Absent speech - Anxiety - Ataxia - Brachycephaly - Bruxism - Chorea - Constipation - Cryptorchidism - Depressed nasal bridge - Depression - Drooling - Dysphagia - Facial hypotonia - Flat midface - Gastroesophageal reflux - Infantile muscular hypotonia - Intellectual disability - Low-set ears - Macrocephaly - Macrotia - Malar flattening - Microcephaly - Narrow mouth - Poor eye contact - Progressive - Progressive spasticity - Recurrent respiratory infections - Rigidity - Seizures - Severe global developmental delay - Tented upper lip vermilion - X-linked recessive inheritance - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.