Lujan syndrome

Also known as: LFS, Lujan-Fryns syndrome, X-linked intellectual deficit with marfanoid habitus, X-linked mental retardation with marfanoid habitus, XLMR with marfanoid features


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Lujan syndrome is a condition characterized by intellectual disability, behavioral problems, and certain physical features. It occurs almost exclusively in males.

The intellectual disability associated with Lujan syndrome is usually mild to moderate. Behavioral problems can include hyperactivity, aggressiveness, extreme shyness, and excessive attention-seeking. Some affected individuals have features of autism or related developmental disorders affecting communication and social interaction. A few have been diagnosed with psychiatric problems such as delusions and hallucinations.

Characteristic physical features of Lujan syndrome include a tall, thin body and an unusually large head (macrocephaly). Affected individuals also have a long, thin face with distinctive facial features such as a prominent top of the nose (high nasal root); a short space between the nose and the upper lip (philtrum); a narrow roof of the mouth (palate); crowded teeth; and a small chin (micrognathia). Almost all people with this condition have weak muscle tone (hypotonia).

Additional signs and symptoms of Lujan syndrome can include abnormal speech, heart defects, and abnormalities of the genitourinary system. Many affected individuals have long fingers and toes with an unusually large range of joint movement (hyperextensibility). Seizures and abnormalities of the tissue that connects the left and right halves of the brain (corpus callosum) have also been reported in people with this condition.

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The Lujan-Fryns syndrome or X-linked mental retardation (XLMR) with marfanoid habitus syndrome is a syndromic X-linked form of intellectual disability, associated with tall, marfanoid stature, distinct facial dysmorphism and behavioral problems.

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Medical Term Other Names Description
Narrow face Decreased horizontal dimension of face, Thin facies, Decreased breadth of face, Decreased transverse dimension of face, Horizontal hypoplasia of face, Transverse hypoplasia of face, Narrow facies, Thin face, Decreased width of face [more] Bizygomatic (upper face) and bigonial (lower face) width are both more than 2 standard deviations below the mean (objective); or, an apparent reduction in the width of the upper and lower face (subjective).
Short chin Vertical deficiency of chin, Small chin, Decreased height of chin, Short lower third of face [more] Decreased vertical distance from the vermilion border of the lower lip to the inferior-most point of the chin.
Dental crowding Tooth size discrepancy, Crowded teeth, Dental overcrowding, Inadequate arch length for tooth size, Tooth mass arch size discrepancy, Overcrowding of teeth [more] Overlapping teeth within an alveolar ridge.
Intellectual disability Nonprogressive intellectual disability, Poor school performance, Mental-retardation, Dull intelligence, Nonprogressive mental retardation, Mental deficiency, Mental retardation, nonspecific, Low intelligence [more] Subnormal intellectual functioning which originates during the developmental period. Intellectual disability, previously referred to as mental retardation, has been defined as an IQ score below 70.
Seizures Epilepsy Seizures are an intermittent abnormality of the central nervous system due to a sudden, excessive, disorderly discharge of cerebral neurons and characterized clinically by some combination of disturbance of sensation, loss of consciousness, impairment of psychic function, or convulsive movements. The term epilepsy is used to describe chronic, recurrent seizures.
Macrocephaly Big skull, Increased size of head, Large head, Increased size of skull, Large head circumference, Big head, Large calvaria, Increased size of cranium, Large skull, Big cranium, Large cranium, Big calvaria, Macrocrania, Megacephaly [more] Occipitofrontal (head) circumference greater than 97th centile compared to appropriate, age matched, sex-matched normal standards. Alternatively, a apparently increased size of the cranium.
Autism Autism is a neurodevelopmental disorder characterized by impaired social interaction and communication, and by restricted and repetitive behavior. Autism begins in childhood. It is marked by the presence of markedly abnormal or impaired development in social interaction and communication and a markedly restricted repertoire of activity and interest. Manifestations of the disorder vary greatly depending on the developmental level and chronological age of the individual (DSM-IV).
Delusions A belief that is pathological and is held despite evidence to the contrary.
Hyperactivity Hyperactive behavior
Micrognathia Lower jaw hypoplasia, Mandibular deficiency, Retrusion of lower jaw, Hypoplastic mandible condyle, Small mandible, Decreased projection of lower jaw, Micrognathia of lower jaw, Mandibular retrognathia, Mandibular retrusion, Decreased size of lower jaw, Micromandible, Underdevelopment of lower jaw, Hypotrophic mandible, Hypotrophic lower jaw, Robin mandible, Little mandible, Underdevelopment of mandible, Small jaw, Decreased size of mandible, Hypoplastic mandible, Little lower jaw, Decreased projection of mandible, Mandibular micrognathia, Lower jaw retrognathia [more] Developmental hypoplasia of the mandible.
Abnormality of cardiovascular system morphology Cardiovascular malformations, Heart defect Any structural anomaly of the heart and great vessels.
Aggressive behavior Aggressiveness, Aggressive behaviour, physical aggression, Aggression [more] Aggressive behavior can denote verbal aggression, physical aggression against objects, physical aggression against people, and may also include aggression towards oneself.
Abnormality of the genitourinary system Genitourinary abnormality, Genitourinary tract malformation, Urogenital anomalies [more] The presence of any abnormality of the genitourinary system.
Long fingers The middle finger is more than 2 SD above the mean for newborns 27 to 41 weeks EGA or above the 97th centile for children from birth to 16 years of age AND the five digits retain their normal length proportions relative to each other (i.e., it is not the case that the middle finger is the only lengthened digit), or, Fingers that appear disproportionately long compared to the palm of the hand.
Abnormal facial shape Dysmorphic facial features, Facial Dysmorphism, Deformity of face, Distortion of face, Unusual facial appearance, Funny looking face, Dysmorphic facies, Unusual facies, Malformation of face, Abnormal morphology of the face, Distinctive facies [more] An abnormal morphology (form) of the face or its components.
Behavioral abnormality Psychiatric disturbances, Behavioral problems, Behavioral/psychiatric abnormalities, Behavioural/Psychiatric abnormality [more] An abnormality of mental functioning including various affective, behavioural, cognitive and perceptual abnormalities.
Disproportionate tall stature Marfanoid habitus, Reduced upper-lower segment ratio, Dolichostenomelia [more] A tall and slim body build with increased arm span to height ratio (>1.05) and a reduced upper-to-lower segment ratio (<0.85), i.e., unusually long arms and legs. The extremities as well as the hands and feet are unusually slim.

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