Brachydactyly-arterial hypertension syndrome: A Patient Guide

Brachydactyly-arterial hypertension syndrome, also known as HTNB or Bilginturan syndrome, is an ultra-rare genetic condition that uniquely links physical traits with internal vascular health. It is characterized by the combination of Brachydactyly Type E—a shortening of the fingers and toes—and severe high blood pressure that typically begins in childhood or adolescence ^[1]. Unlike most common forms of high blood pressure, the hypertension in this syndrome is not primarily driven by salt retention or kidney disease. Rather, it is driven by a fundamental change in how the blood vessels themselves function ^[2]. However, usual lifestyle measures still support cardiovascular health, though they cannot replace medication.

What This Guide Can and Cannot Do: This guide provides educational information about the syndrome. An individual blood-pressure plan must come from your treating team, and experiencing emergency symptoms overrides reading this guide.

The root of this condition lies in a specific “gain-of-function” mutation in the PDE3A gene ^[1]. This genetic change causes an enzyme in the blood vessel walls and bone growth plates to become overactive, leading to narrower, more rigid arteries and the characteristic shortening of the hand and foot bones ^[2][3]. Because the syndrome follows an autosomal dominant inheritance pattern, it is often seen across multiple generations of a family, where each child of an affected parent has a 50% chance of inheriting the variant ^[1].

If left untreated, the severe hypertension associated with HTNB carries a significant risk of early stroke or other vascular complications before the age of 50 ^[4]. However, this risk can be managed. The hypertension in this syndrome is remarkably medically responsive, meaning that with an individualized combination of standard blood pressure medications and consistent monitoring, individuals can achieve safer levels and significantly lower their risk of long-term damage ^[5][6].

A notable and encouraging feature reported in some families with this syndrome is a medical paradox: despite enduring extreme levels of high blood pressure, the heart and kidneys of affected individuals appear relatively spared for a time ^[7]. While common hypertension frequently leads to thickened heart muscles or kidney failure, the PDE3A mutation may offer a unique form of relative protection to these specific organs ^[2]. However, patients can still develop heart, kidney, eye, or brain complications, so normal tests today do not remove the need for surveillance. This diagnosis is a vital tool for focused prevention, allowing you and your care team to target the vascular system directly and maintain a high quality of life ^[4].