ABSTRACT
Dyssegmental dysplasia (DD) is a severe skeletal dysplasia comprised of two subtypes: lethal Silverman-Handmaker type (DDSH) and nonlethal Rolland-Desbuquois type (DDRD). DDSH is caused by biallelic pathogenic variants in HSPG2 encoding perlecan, whereas the genetic cause of DDRD remains undetermined. Schwartz-Jampel syndrome (SJS) is also caused by biallelic pathogenic variants in HSPG2 and is an allelic disorder of DDSH. In SJS and DDSH, 44 and 8 pathogenic variants have been reported in HSPG2, respectively. Here, we report that five patients with DDRD carried four pathogenic variants in HSPG2: c.9970 G > A (p.G3324R), c.559 C > T (p.R187X), c7006 + 1 G > A, and c.11562 + 2 T > G. Two patients were homozygous for p.G3324R, and three patients were heterozygous for p.G3324R. Haplotype analysis revealed a founder haplotype spanning 85,973 bp shared in the five patients. SJS, DDRD, and DDSH are allelic disorders with pathogenic variants in HSPG2.
Subject(s)
Haplotypes , Heparan Sulfate Proteoglycans , Osteochondrodysplasias , Female , Humans , Male , Alleles , Bone Diseases, Developmental/genetics , Bone Diseases, Developmental/pathology , Founder Effect , Heparan Sulfate Proteoglycans/genetics , Mutation , Osteochondrodysplasias/genetics , Osteochondrodysplasias/pathology , Fetal DiseasesABSTRACT
Anti-Diego b (Di(b) ) antibodies, rare antibodies against red blood cell antigens, can cause severe hemolysis. We report a patient who most likely acquired anti-Di(b) antibodies during pregnancy. The patient was a 39-year-old Japanese woman who delivered by cesarean section at 38 weeks of gestation. She required a second operation to treat re-bleeding of the surgical scar, but it was difficult to schedule this surgery because we could not obtain enough blood for transfusion due to the presence of anti-Di(b) antibodies. These antibodies were likely acquired during pregnancy; she did not have irregular antibodies at 11 weeks of gestation. We speculate that she became sensitized to fetal blood due to feto-maternal hemorrhage. The infant had no hemolytic conditions. Testing for the presence of irregular antibodies should be performed during late stages of pregnancy as well as early stages.
