Kleefstra syndrome

Classification according to ICD-10
Q93.5	Other deletions of a part of a chromosome
Q87.8	Other specified congenital malformation syndromes, not elsewhere classified
ICD-10 online (WHO version 2019)

The Kleefstra syndrome (9q34.3 deletion syndrome) is a very rare, to the chromosomal Deletionssyndromen associated congenital disease with the main features of mental retardation , facial dysmorphia , hypotonia and other abnormalities.

Synonyms are: Kleefstra syndrome due to microdeletion 9q34; Kleefstra syndrome due to point mutations

The name refers to the first author of the first description from 2009 by the Dutch human geneticist Tjitske Kleefstra and colleagues.

distribution

The frequency is unknown; 114 patients have been reported to date. The inheritance is autosomal dominant .

root cause

Of the disease are either point mutations in EHMT1 - gene or, more commonly microdeletions on chromosome 9 locus q34.3 based encoding the euchromatic histone lysine N-methyltransferase. 1

Clinical manifestations

Clinical criteria are:

Manifestation in newborn to toddler age
Facial abnormalities with brachy , microcephaly , midface hypoplasia , abnormal eyebrows and upper lip, progeny and protruding tongue .

Misaligned teeth

Muscle hypotension with developmental delay

Mental disability

congenital heart defects , kidney malformations, epilepsy , hearing loss , obesity

Differential diagnosis

Must be distinguished are the down , the Pitt-Hopkins , the Smith-Magenis- that Rett and microdeletion 2q23.1 .

literature

K. Vermeulen, A. de Boer, JG Janzing, DA Koolen, CW Ockeloen, MH Willemsen, FM Verhoef, PA van Deurzen, L. van Dongen, H. van Bokhoven, JI Egger, WG Staal, T. Kleefstra: Adaptive and maladaptive functioning in Kleefstra syndrome compared to other rare genetic disorders with intellectual disabilities. In: American journal of medical genetics. Part A. [electronic publication before printing] May 2017, doi: 10.1002 / ajmg.a.38280 , PMID 28498556 .
K. Hadzsiev, K. Komlosi, M. Czako, B. Duga, R. Szalai, A. Szabo, E. Postyeni, T. Szabo, G. Kosztolanyi, B. Melegh: Kleefstra syndrome in Hungarian patients: additional symptoms besides the classic phenotype. In: Molecular cytogenetics. Vol. 9, 2016, p. 22, doi: 10.1186 / s13039-016-0231-2 , PMID 26918030 , PMC 4766673 (free full text).

Individual evidence

↑ ^a ^b ^c Kleefstra syndrome. In: Orphanet (Rare Disease Database).
↑ T. Kleefstra, WA van Zelst-Stam, WM Nillesen, V. Cormier-Daire, G. Houge, N. Foulds, M. van Dooren, MH Willemsen, R. Pfundt, A. Turner, M. Wilson, J. McGaughran, A. Rauch, M. Zenker, MP Adam, M. Innes, C. Davies, AG López, R. Casalone, A. Weber, LA Brueton, AD Navarro, MP Bralo, H. Venselaar, SP Stegmann, HG Yntema , H. van Bokhoven, HG Brunner: Further clinical and molecular delineation of the 9q subtelomeric deletion syndrome supports a major contribution of EHMT1 haploinsufficiency to the core phenotype. In: Journal of medical genetics. Vol. 46, No. 9, September 2009, pp. 598-606, doi: 10.1136 / jmg.2008.062950 , PMID 19264732 .
↑ Kleefstra syndrome. In: Online Mendelian Inheritance in Man . (English)

Web links

[Orpha-1] Kleefstra syndrome. In: Orphanet (Rare Disease Database).

[2] T. Kleefstra, WA van Zelst-Stam, WM Nillesen, V. Cormier-Daire, G. Houge, N. Foulds, M. van Dooren, MH Willemsen, R. Pfundt, A. Turner, M. Wilson, J. McGaughran, A. Rauch, M. Zenker, MP Adam, M. Innes, C. Davies, AG López, R. Casalone, A. Weber, LA Brueton, AD Navarro, MP Bralo, H. Venselaar, SP Stegmann, HG Yntema , H. van Bokhoven, HG Brunner: Further clinical and molecular delineation of the 9q subtelomeric deletion syndrome supports a major contribution of EHMT1 haploinsufficiency to the core phenotype. In: Journal of medical genetics. Vol. 46, No. 9, September 2009, pp. 598-606, doi: 10.1136 / jmg.2008.062950 , PMID 19264732 .

[3] Kleefstra syndrome. In: Online Mendelian Inheritance in Man . (English)