Severe Congenital Neutropenia-Developmental Delay Syndrome (SRP54 Deficiency): A Patient Guide

Severe congenital neutropenia-developmental delay syndrome, also known as SRP54 deficiency, is a rare genetic condition that can affect multiple systems in the body. It was first identified by researchers in 2017. While only a small number of cases (approximately 38) had been documented in medical literature as of 2023, published case counts are an incomplete measure and the actual number of affected individuals may be slightly higher ^[1]. This condition is primarily defined by a severe shortage of neutrophils, the white blood cells responsible for fighting bacterial infections, which typically appears within the first few months of life ^[2][3].

Because the body lacks these essential “first responders,” children with SRP54 deficiency are at a significantly higher risk for recurring or severe infections ^[4]. For parents, the most critical safety measure is recognizing that a fever in a neutropenic child is a medical emergency that requires immediate evaluation for a possible serious infection, and often requires intravenous (IV) antibiotics ^[5][6].

Beyond the immune system, the condition may include “extrahematologic” (outside the blood) features. These can include delays in meeting developmental milestones and issues with the pancreas, known as exocrine pancreatic insufficiency (EPI), which can interfere with the digestion of fats and nutrients ^[7][3]. It is important to know that not every child has these extra features.

Managing this syndrome requires a personalized approach and a multidisciplinary team of specialists, including hematologists, gastroenterologists, and developmental pediatricians ^[7][8]. The primary treatment for low white blood cell counts is often a daily injection called G-CSF, though the response to this medication varies greatly; some children require higher doses, while others may eventually need a Hematopoietic Stem Cell Transplant (HSCT) if their counts remain dangerously low ^[4][2][9].

While the rarity of SRP54 deficiency means there is still much to learn, long-term care focuses on preventative surveillance. Your specialist may recommend periodic marrow examinations, often about yearly in some protocols, to monitor the “blood-making factory” for any changes, as well as regular check-ups to support your child’s growth and development ^[4][10]. By identifying the condition early and building a dedicated care team, families can focus on providing the specialized support their child needs to navigate these challenges ^[7].