Transient surfactant protein B deficiency in a term infant with severe respiratory failure.
A 38-day-old male infant with persistent pulmonary hypertension and respiratory failure since birth was found to have a complete absence of surfactant protein B (SP-B) along with an aberrant form of SP-C in his tracheal aspirate fluid, findings consistent with the diagnosis of hereditary SP-B deficiency. Surprisingly, SP-B and SP-B messenger ribonucleic acid were present in lung biopsy tissue. However, DNA sequence analysis demonstrated a point mutation in exon 5 of one of the SP-B gene alleles. The infant's mother was found to be a carrier of this mutation. The infant's other SP-B allele did not differ from the published DNA sequence for the SP-B gene. We conclude that this patient had a transient deficiency of SP-B, in contrast to that of previously described infants with irreversible respiratory failure caused by hereditary SP-B deficiency. We recommend that infants with suspected SP-B deficiency have serial analysis of tracheal fluid samples for both SP-B and SP-C before lung biopsy, along with genetic analysis for the known SP-B mutations. We speculate that the new mutation found in one of this patient's SP-B genes was in part responsible for the transient deficiency of SP-B.
Klein
J M
JM
Department of Pediatrics, University of Iowa, Iowa City 52242-1083, USA.
Thompson
M W
MW
Snyder
J M
JM
George
T N
TN
Whitsett
J A
JA
Bell
E F
EF
McCray
P B
PB
Nogee
L M
LM
D005122:Exudates and Transudates / Q000737:chemistry; D006801:Humans; D015151:Immunoblotting; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008661:Metabolism, Inborn Errors / Q000150:complications / Q000235:genetics*; D009154:Mutation; D016133:Polymerase Chain Reaction; D011510:Proteolipids / Q000235:genetics / Q000378:metabolism*; D011663:Pulmonary Surfactants / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism*; D012127:Respiratory Distress Syndrome, Newborn / Q000150:complications / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D013997:Time Factors; D014132:Trachea
D011510:Proteolipids; D011663:Pulmonary Surfactants