What is Lujan-Fryns syndrome?
Lujan syndrome is a rare genetic disease that occurs mainly in males. Its defining facial features are similar to those of Marfan syndrome, including a tall and thin stature.
The other main symptoms of the syndrome include intellectual disability and behavioral issues.
Syndrome Synonyms:
Lujan-Fryns syndrome; Mental Retardation, X-linked, with Marfanoid Habitus; X-linked mental retardation-marfanoid habitus
What gene change causes Lujan-Fryns syndrome?
As an X-linked disorder, mainly males are affected by the syndrome.
Mutations in the MED12 gene are responsible for the syndrome. However, other genes (up to date 56) of X-linked Intellectual Developmental Disorder should be considered.
Syndromes inherited in an X-linked recessive pattern generally only affect males. Males only have one X chromosome, and so one copy of a gene mutation on it causes the syndrome. Females, with two X chromosomes, only one of which will be mutated, are not likely to be affected.
With syndromes inherited in an X-linked dominant pattern, a mutation in just one of the copies of the gene, causes the syndrome. This can be in one of the female X chromosomes, and in the one X chromosomes males have. Males tend to have more severe symptoms than females.
What are the main symptoms of Lujan-Fryns syndrome?
Mild to moderate intellectual disability is a major symptom of the syndrome. Behavioral issues related to the syndrome include hyperactivity, aggression, extreme shyness, and social anxiety as well as extreme attention-seeking behaviors. Some affected individuals may also be diagnosed as on the autism spectrum, and issues with communication and interaction with others are common with the syndrome. In severe cases, delusions and hallucinations may also be potential symptoms.
Unique facial and physical features of the syndrome are a tall stature, a large head, a long face, a prominent top of the nose, a short philtrum (the space between the nose and upper lip), a narrow palate, crowded teeth, and a small chin.
Low muscle tone is also a common symptom associated with the syndrome.
Other possible symptoms include speech delay, seizures, hyperextensibility of the joints, and brain abnormalities.
Possible clinical traits/features:
Flexion contracture, Emotional lability, Dental crowding, Deep philtrum, Agenesis of corpus callosum, Disproportionate tall stature, Intellectual disability, Narrow face, Low frustration tolerance, Low-set ears, Long face, Long nose, Narrow nasal bridge, Joint laxity, Micrognathia, Pectus excavatum, X-linked recessive inheritance, Ventricular septal defect, Frontal bossing, Prominent forehead, Short philtrum, Thin upper lip vermilion, Macrocephaly, Impaired social interactions, High palate, Hyperactivity, Prominent nasal bridge, Nasal speech, Generalized hypotonia, Abnormality of the genitourinary system, Hypoplasia of the maxilla, Seizure, Psychosis, Obsessive-compulsive behavior, Open mouth, Autism, Atrial septal defect, Broad thumb, Arachnodactyly, Dilatation of ascending aorta, Aggressive behavior, Abnormality of the rib cage, Abnormally folded helix.
How is it diagnosed?
To find out if someone has a diagnosis of Lujan-Fryns syndrome, it is important to have a consultation and evaluation with a clinical genetic specialist. Specialists may also suggest specific genetic testing or other types of tests to help reach a diagnosis. FDNA’s AI technology can help speed up the diagnostic process by analyzing facial features and other health information.