We present two siblings with completely identical clinical findings, suggestive of a previously unreported familial syndrome. Major findings of the siblings involve three systems; pulmonary system presented with pulmonary arterial hypertension, cardiac system presented with secundum type ASD, and hematopoietic system presented with intermittent neutropenia, lymphopenia, monocytosis, anemia, and dramatic dysplastic changes in all lineages. The siblings also shared several minor abnormalities; pectus carinatum, long fingers, proximally located thumb, broad nasal bridge, and high arched palate. The male proband had bilateral inguinal hernias and undescended testes, as well. Having the same findings in these siblings may suggest a genetic basis; either an autosomal recessive disorder or a germline mosaicism for a dominant mutation. Initial studies to define the genetic basis of our patients revealed a BMPR2 polymorphism in intron 4 in only one sibling, which was also present in unaffected maternal relatives.
Acknowledgement This study was supported partly by State Planning Organization (No: 2006K120 640-06-03) from Turkey.