[MIM 305 000, 300 240]

Very rare: < 1/106. Autosomal dominant or recessive or X-linked transmission .

Severe variant of congenital dyskeratosis (see this topic). Mutation of the DCK1 gene on Xq28 that codes for dyskerine, a protein of the nucleolus which interacts with the complex of RNA telomerase. Mutations of other genes as TERT, RTEL1, TINF2 and SNM1B also involved in the function of telomerase, can also be associated with this disease.

Association of:

-         intrauterine growth retardation

-         microcephaly

-         cerebellar hypoplasia

-         progressive bone marrow failure

-         combined immune deficiency

-         muco-cutaneous lesions: often late-onset hyperpigmentation, dystrophy of the nails, leukoplakia of the  oral and gastrointestinal mucosae.

Often early death by lung infection or bone marrow failure. Bone marrow transplantation has been attempted in some cases.

Anesthetic implications: 

check complete blood count and lung function; fragile teeth. 

References : 

-        Sekerci AE, Keskinrüzgar A, Sisman Y, Unal E, Karakukcu M, Ozdemir MA. 
Oral and dental findings of the longest surviving patient with Hoyeraal-Hreidarsson syndrome. 
J Oral Health Comm Dent 2014; 8: 65-9.

-         Lim BC, Yoo S-K, Lee S, Shin J-Y et al. 
Hoyeraal-Hreidarsson syndrome with DKC1 mutation identified by whole-exome sequencing. 
Gene 2014; 546:425-9.

Updated: March 2019