Reticular Dysgenesis: A Rare Immunodeficiency in a Neonate With Cytopenias and Bacterial Sepsis

Severe combined immunodeficiency (SCID) consists of a group of disorders defined by abnormal B and T cell development that typically results in death within the first year of life if undiagnosed or untreated. Reticular dysgenesis (RD) is a rare but especially severe form of SCID that is caused by adenylate kinase 2 deficiency and is characterized not only by lymphopenia but also by profound neutropenia. RD predisposes patients to viral and fungal infections typical of SCID as well as serious bacterial infections atypical in the neonatal period in other SCID types. RD is also associated with sensorineural hearing loss not typically seen in other forms of SCID. Without rapid diagnosis and curative hematopoietic stem cell transplantation, RD is fatal within days to months due to overwhelming bacterial infection. The inclusion of the T cell receptor excision circle assay nationally in 2017 on the newborn screen has facilitated diagnosis of SCID in the neonatal period. This case reports on a male infant with RD who presented after preterm birth with severe cytopenias and a gastrointestinal anomaly and ultimately developed severe bacterial sepsis. Postmortem bone marrow evaluation and panel-based gene sequencing identifying 2 novel variants in the adenylate kinase 2 gene provided confirmation for a diagnosis of RD. This case emphasizes the importance of thorough diagnostic evaluation, including the newborn screen, in neonates and infants with persistent and unexplained cytopenias. Prompt hematology and/or immunology referral is advised for disease management and to facilitate hematopoietic stem cell transplantation to optimize long-term survival.

Congenital Hypothyroidism

Congenital hypothyroidism (CH) is a disorder of thyroid hormone deficiency which develops secondary to incomplete thyroid development or inadequate thyroid hormone production. State-mandated newborn screening throughout the United States has increased the detection rate of CH, allowing for early intervention. Although the overall mortality rate of CH is low, delayed or omitted treatment can lead to devastating neurocognitive outcomes. As such, CH is regarded as the leading cause of preventable intellectual disability in children. Early identification, facilitated by astute neonatal nursing and medical care, is contingent upon an active working knowledge of the disease process and awareness of the limitations of the newborn screen.

Abnormal Newborn Screen in an Ex-premature Infant fed Goat Milk

Newborn screening is an important tool in the early diagnosis or detection of rare genetic and metabolic conditions. There are external factors that may influence results. One such is infant nutrition. This article discusses the case of a three month old infant with an abnormal newborn screen in the setting of being fed whole goat milk as well as the importance of reviewing infant nutrition with parents.