14. ULUSAL TIBBİ GENETİK KONGRESİ “Uluslararası Katılımlı”, Ankara, Türkiye, 20 - 22 Kasım 2020, ss.69
Acromesomelic Dysplasia Maroteaux type (AMDM) which belongs
to the group of acromesomelic dysplasias is an extremely rare skeletal disorder
described by severe shortening of the forelimbs and disproportionate short stature.
AMDM is an autosomal recessive genetic disorder with a prevalence of
1/1,000,000. Clinical features of the syndrome are short broad fingers, square flat feet, and
shortening of the long bones, radial bowing, dolichocephaly, frontal bossing,
and normal facial appearance and intelligence This
condition is caused by homozygous or compound heterozygous mutations in the
natriuretic peptide receptor 2 (NPR2) gene, located on
chromosome 9p13. NPR2 gene encodes
natriuretic peptide receptor B (NPR-B) that plays a critical role in endochondral
ossification, which is responsible for longitudinal growth in limbs and
vertebrae. Here we reported two Turkish siblings
presenting with severe dwarfism and atypic skeletal findings. Next Generation
sequence analysis revealed a novel pathogenic variant in NPR2 (c. 661G>A, p. (Gly221Arg)) which
was found to be homozygous in the siblings. Both siblings were identified with
a novel missense NPR2 mutation and were
diagnosed with AMDM. Their parents are carriers of the same variant.
Keywords: Acromesomelic Dysplasia Maroteaux Type, A Novel NPR2 Mutation