Lujan-Fryns Syndrome

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Classification according to ICD-10
F70.1 Mild intellectual disorder: A marked behavioral disorder that requires observation or treatment
ICD-10 online (WHO version 2019)

The Lujan-Fryns syndrome (LFS), also known as marfanoid retardation X-linked mental habit syndrome called, is a very rare X-linked inherited disease . Another name is Mental retardation, X-linked 14 .

Clinical picture

Patient with Lujan-Fryns Syndrome

Lujan-Fryns syndrome is characterized by X-linked mental retardation , tall and marfanoid stature , clear facial dysmorphisms and behavioral problems .

The patients are tall, but reach a normal final size. The high forehead, a long, narrow face, a small lower jaw and an underdevelopment ( hypoplasia ) of the upper jaw , a long nose with a high, narrow nasal root, including a short but deep philtrum , as well as a thin upper lip and a high palate , are typical features in Face of the LFS patient. Typical characteristics of the extremities are long, hyperextensible fingers and toes, short big toes and long second toes.

After puberty, the marfanoid habit develops more clearly. Secondary sex development is normal. Nasal language and general muscle hypotension are typical .

The behavioral problems manifest themselves in emotional instability, hyperactivity and shyness. Psychiatric abnormalities such as psychotic confusion, hallucinations and even schizophrenia are possible . The patients are mentally slightly to moderately disabled.

frequency

Due to inheritance, the disease primarily affects males. The prevalence of Lujan-Fryns syndrome is unknown. It is naturally more widespread in mentally retarded and psychiatric patients.

genetics

The cause of the Lujan-Fryns syndrome are mutations in the MED12 gene ( mediator complex subunit 12 ). The cases examined so far are a missense mutation , of the type p.N1007S. The affected gene is located on the X chromosome, gene locus 13.1 .. It is 25 kb in size and consists of 44 exons . The gene product is a subunit of the mediator complex ( mediator , also called thyroid hormone receptor-associated protein (TRAP, thyroid hormone receptor-associated protein ) or vitamin D receptor interacting protein (DRIP, vitamin D receptor interacting protein)), which consists of 28 subunits is constructed and weighs 1.2 M Dalton .

Lujan-Fryns syndrome is allelic with FG syndrome .

diagnosis

Until 2007, Lujan-Fryns syndrome could only be diagnosed clinically because the cause of the disease was unknown. After the affected gene has been identified, the diagnosis can now in principle also be carried out by DNA analysis . If the diagnosis is made based on the clinical picture so are the differential diagnosis , the Fragile X Syndrome , schizophrenia , Marfan syndrome and homocystinuria delineate.

therapy

There is no specific treatment for Lujan-Fryns syndrome. The disease has so far been incurable. In psychological care, the focus should be on intellectual development and attention should be paid to psychoses as early as possible.

Initial description

Lujan-Fryns syndrome was first described in 1984 by the US pediatrician J. Enrique Lujan and colleagues in four male patients. Three years later, the Belgian human geneticist Jean-Pierre Fryns described two cases with the same symptoms. Lujan-Fryns syndrome was named after the two scientists.

See also

Individual evidence

  1. ↑ a b c d e G. Van Buggenhout, JP Fryns: Lujan-Fryns syndrome (mental retardation, X-linked, marfanoid habitus). In: Orphanet Journal of Rare Diseases. Volume 1, 2006, p. 26, ISSN  1750-1172 . doi: 10.1186 / 1750-1172-1-26 . PMID 16831221 . PMC 1538574 (free full text). (Review article in Open Access ).
  2. ↑ a b c d C. E. Schwartz, PS Tarpey et al. a .: The original Lujan syndrome family has a novel missense mutation (p.N1007S) in the MED12 gene. In: Journal of medical genetics. Volume 44, Number 7, July 2007, pp. 472-477, ISSN  1468-6244 . doi: 10.1136 / jmg.2006.048637 . PMID 17369503 . PMC 2597996 (free full text).
  3. ↑ M. De Hert, D. Steemans et al. a .: Lujan-Fryns syndrome in the differential diagnosis of schizophrenia. In: American journal of medical genetics. Volume 67, Number 2, April 1996, pp. 212-214, ISSN  0148-7299 . doi : 10.1002 / (SICI) 1096-8628 (19960409) 67: 2 <212 :: AID-AJMG13> 3.0.CO; 2-M . PMID 8723050 .
  4. ^ JE Lujan, ME Carlin, HA Lubs: A form of X-linked mental retardation with marfanoid habitus. In: American journal of medical genetics. Volume 17, Number 1, January 1984, pp. 311-322, ISSN  0148-7299 . doi: 10.1002 / ajmg.1320170124 . PMID 6711603 .
  5. ↑ JP Fryns, M. Buttiens: X-linked mental retardation with marfanoid habitus. In: American journal of medical genetics. Volume 28, Number 2, October 1987, pp. 267-274, ISSN  0148-7299 . doi: 10.1002 / ajmg.1320280202 . PMID 3322000 . (Review).

further reading

  • MS Williams: Neuropsychological evaluation in Lujan-Fryns syndrome: commentary and clinical report. In: American journal of medical genetics. Part A. Volume 140, Number 24, December 2006, pp. 2812-2815, ISSN  1552-4825 . doi: 10.1002 / ajmg.a.31501 . PMID 17103446 .
  • KN Purandare, TN Markar: Psychiatric symptomatology of Lujan-Fryns syndrome: an X-linked syndrome displaying Marfanoid symptoms with autistic features, hyperactivity, shyness and schizophreniform symptoms. In: Psychiatric genetics. Volume 15, Number 3, September 2005, pp. 229-231, ISSN  0955-8829 . PMID 16094260 .
  • J. Donders, H. Toriello, S. van Doornik: Preserved neurobehavioral abilities in Lujan-Fryns syndrome. In: American journal of medical genetics. Volume 107, Number 3, January 2002, pp. 243-246, ISSN  0148-7299 . PMID 11807907 .

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