Bone Marrow Exam Can Be Crucial in Diagnosing Rare Porphyria

A baby girl was found to have congenital erythropoietic porphyria, highlighting the importance of closely examining the bone marrow for diagnosing this rare form of porphyria.

Her case was described in the study, “Bone marrow erythroid cell inclusions reveal congenital erythropoietic porphyria,” published in the British Journal of Haematology, by a team of researchers in France.

The baby was born full-term by cesarean section, weighing 2.7 kg or about 6 lbs. Routine ultrasounds performed during pregnancy revealed the right lower chamber of her heart was enlarged.

Following birth, she had difficulty breathing, hepatosplenomegaly (an enlarged liver and spleen), abnormal bruising, and red urine.

Blood tests revealed abnormally low levels of red blood cells, which transport oxygen through the bloodstream, and of platelets — small cell fragments that play a key role in blood clotting. The baby also had abnormally high levels of ferritin — a protein that contains iron and is normally used to estimate the amount of iron stored in the body — and lactate dehydrogenase, a marker of tissue damage.

Clinicians in France initially suspected the infant might have familial hemophagocytic lymphohistiocytosis, a rare condition that causes the immune system to produce excessive amounts of certain types of inflammatory immune cells.

However, an examination of the baby’s bone marrow showed features inconsistent with this disorder. The infant also had erythroid hyperplasia, or unusually high numbers of immature red blood cells, as well as cells containing crystalized porphyrins, a key feature of porphyria.

Further urine and blood tests confirmed the baby’s abnormally high levels of porphyrins, which eventually led to the diagnosis of congenital erythropoietic porphyria. Of note, porphyrins are heme precursors that tend to build in different tissues and organs in people with porphyria, due to disruptions in the heme production pathway. (Heme is a molecule that enables red blood cells to transport oxygen in the bloodstream.)

Congenital erythropoietic porphyria, also known as CEP or Günther disease, is one of the rarest types of porphyria. It usually manifests in childhood and is caused mainly by mutations in the UROS gene.

According to the scientists, diagnosing CEP can be challenging because the disease’s symptoms are not very specific. Nonetheless, an early diagnosis is important because it allows for prompt treatment, avoiding potential long-term complications like liver damage.

“Bone marrow examination may be crucial in making this diagnosis,” the researchers wrote.