The C/EBPε gene contains a frameshift mutation in a patient with SGD.

(A) Representative sequence chromatographs from a normal and an SGD patient from nucleotides 1005 through 1024 based on the previously deposited sequence.16 The nucleotide sequence is denoted across the top of the chromatograph. The arrows indicate the boundary between exon 2 and intron 2. The codon encoding amino acid residue lysine 170 (K170) is overlined in the normal sequence. The sequence was determined from 3 separate PCR reactions on the genomic DNA. A total of 12 clones from 3 separate PCR reactions were sequenced from both directions to verify the mutation. (B) Schematic drawing of the C/EBPε genomic locus indicates the 3 exons, translational start codons (ATG) for each isoform, the basic region–leucine zipper (bZIP) domain, and the 2 alternative promoters, Pα and Pβ. The downward arrowhead indicates the location of the A-nucleotide insertion in both panels. This would shift the open reading frame at the K170 codon and result in the lack of the bZIP domain in isoforms p32, p30, p27, and p14. The upward arrowhead indicates the position of CA-repeat microsatellite that is 35 bp 3′ of the polyadenylation site.