Variable clinical presentation of Shwachman-Diamond syndrome: update from the North American Shwachman-Diamond Syndrome Registry.

OBJECTIVES: To investigate the range of clinical presentations for Shwachman-Diamond syndrome (SDS) with the long-term goal of improving diagnosis. STUDY DESIGN: We reviewed the North American Shwachman-Diamond Syndrome Registry. Genetic reports of biallelic Shwachman-Bodian-Diamond syndrome mutations confirming the diagnosis of SDS were available for 37 patients. RESULTS: Neutropenia was the most common hematologic abnormality at presentation (30/37, 81%); however, only 51% (19/37) of patients presented with the classic combination of neutropenia and steatorrhea. Absence of pancreatic lipomatosis on ultrasound or computed tomography scan, normal fecal elastase levels, and normal skeletal survey do not rule out the diagnosis of SDS. SDS was diagnosed in 2 asymptomatic siblings of SDS probands. Twenty-four of 37 patients (65%) had congenital anomalies. CONCLUSION: Our cohort reveals a broad range of clinical presentation for SDS. Clues to the underlying diagnosis of SDS included cytopenias with a hypocellular marrow, congenital anomalies, family history, and myelodysplasia with clonal abnormalities frequently found in SDS. Reliance on classic clinical criteria for SDS would miss or delay diagnosis of a significant subset of patients with SDS.

Strong evidence for autosomal dominant inheritance of severe congenital neutropenia associated with ELA2 mutations.

OBJECTIVE: To investigate cases of severe congenital neutropenia (SCN) to ascertain SCN inheritance after determining that the same sperm donor was used by 4 different families to impregnate mothers. STUDY DESIGN: Because the donor sperm was not available, alternative methods were used to determine whether the sperm donor transmitted SCN. DNA isolated from leukocytes was used to sequence the ELA2 gene in the affected children and their mothers. ELA2 was amplified by polymerase chain reaction (PCR), and the product was sequenced. PCR was also performed with genomic DNA from the mothers and affected children using a set of 22 microsatellite PCR primers on chromosomes 14 and 19 to establish linkage to the paternal allele. RESULTS: None of the mothers had a mutation in ELA2, but all 5 affected children had the same mutation affecting the fourth exon at site S97L. Linkage mapping analysis confirmed that all affected children had the same paternal allele on chromosome 19, which contains ELA2. CONCLUSIONS: Our findings indicate that the father provided consistent haplotypes leading to the expression of SCN in all affected children, supporting an autosomal dominant inheritance in which ELA2 mutations occur.