Abnormal bone mineral content and density in people with tetrasomy 18p

Abstract

Tetrasomy 18p is a rare chromosomal abnormality, resulting from an additional iso‐chromosome composed of two copies of the short arm. It is characterized by craniofacial abnormalities, neuromuscular dysfunction, and developmental delay. The Chromosome 18 Clinical Research Center has established the largest cohort of individuals with this rare genetic condition. Here, we describe a case series of 21 individuals with tetrasomy 18p who have a previously unreported clinical finding: low bone mineral density. Most individuals met criteria for low bone density despite being relatively young (mean age of 21 years). Clinicians providing care to individuals affected by Tetrasomy 18p should be aware of their increased risk for decreased bone density and pathological fractures.

Prenatal genetic diagnosis of tetrasomy 18p from maternal trisomy 18p: a case report

“…Additionally, they have dysmorphic features, abnormal brain MRI (63%), central hypotonia (49.6%), acquired microcephaly (47.7%), strabismus (45%), cryptorchidism (17.4%), scoliosis/kyphosis (37%), recurrent otitis media (34.6%), and congenital heart disease (23.7%) [ 11 , 12 ]. Furthermore, tetrasomy 18p patients have lower bone mineral density than that of normal healthy individuals [ 13 ], recurring eye and ocular adnexa, and distinctive facial features associated with tetrasomy 18p [ 14 ]. Due to the lack of specific morphologic features that characterize tetrasomy 18p syndrome, a prenatal ultrasound diagnosis of tetrasomy 18p syndrome is difficult due to the absence of obvious malformations.…”