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X-linked severe combined immunodeficiency syndrome: the first Korean case with gamma c chain gene mutation and subsequent genetic counseling.

Jo EK, Kumaki S, Wei D, Tsuchiya S, Kanegane H, Song CH, Noh HY, Kim YO, Kim SY, Chung HY, Kim YH, Kook H - J. Korean Med. Sci. (2004)

Bottom Line: The patient had a C-to-T point mutation at nucleotide position 690, one of the hot spots, resulting in a single amino acid substitution of cysteine for arginine (R226C), as determined by direct sequencing and PCR-RFLP.Percutaneous umbilical cord blood sampling was performed at the 6-month of gestation in a subsequent pregnancy.As the immunophenotype of the fetus showed an identical pattern, the pregnancy was terminated and genetic analysis of the abortus confirmed recurrence.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology, College of Medicine, Chungnam National University, Daejeon, Korea.

ABSTRACT
X-linked severe combined immunodeficiency (X-SCID) is a rare, life-threatening immune disorder, caused by mutations in the gamma c chain gene, which encodes an essential component of the cytokine receptors for interleukin-2 (IL-2), IL-4, IL-7, IL-9, IL-15, and IL-21. A 13-month-old boy with recurrent infections who had reduced serum immunoglobulin levels and decreased numbers of CD3, CD16/56 cells was evaluated for gamma c chain gene mutation and protein expression. The patient had a C-to-T point mutation at nucleotide position 690, one of the hot spots, resulting in a single amino acid substitution of cysteine for arginine (R226C), as determined by direct sequencing and PCR-RFLP. The patient's mother was a heterozygous carrier. Percutaneous umbilical cord blood sampling was performed at the 6-month of gestation in a subsequent pregnancy. As the immunophenotype of the fetus showed an identical pattern, the pregnancy was terminated and genetic analysis of the abortus confirmed recurrence. This is the first report of the molecular diagnosis of X-SCID in Korea. Genetic analysis of the gamma c chain gene is useful for definite diagnosis and genetic counseling for X-SCID.

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Sequence analysis showing a missense mutation of the common γc chain gene (γc chain) in an X-SCID family. (A) Genomic sequences encompassing a point mutation (C to T) in exon 5 of the γc chain gene from the patient, carrier (mother), and normal control (father) are shown. Arrow, C-to-T transversion. (B) RFLP analysis of the γc chain gene exon 5. Lanes 1 and 2, patient; Lanes 3 and 4, mother; Lanes 5 and 6, normal control. Lanes 1, 3, and 5 show the DNA fragments before restriction enzyme treatment, and Lanes 2, 4, and 6 show the DNA fragments after restriction enzyme treatment. *, Carrier; standard size markers, as indicated on the side. (C) RFLP analysis of amniotic cells. Lanes 1 and 2, fetus; Lanes 3 and 4, normal control. Lanes 1 and 3 show the DNA fragments before restriction enzyme treatment, and Lanes 2 and 4 show the DNA fragments after restriction enzyme treatment.
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Figure 2: Sequence analysis showing a missense mutation of the common γc chain gene (γc chain) in an X-SCID family. (A) Genomic sequences encompassing a point mutation (C to T) in exon 5 of the γc chain gene from the patient, carrier (mother), and normal control (father) are shown. Arrow, C-to-T transversion. (B) RFLP analysis of the γc chain gene exon 5. Lanes 1 and 2, patient; Lanes 3 and 4, mother; Lanes 5 and 6, normal control. Lanes 1, 3, and 5 show the DNA fragments before restriction enzyme treatment, and Lanes 2, 4, and 6 show the DNA fragments after restriction enzyme treatment. *, Carrier; standard size markers, as indicated on the side. (C) RFLP analysis of amniotic cells. Lanes 1 and 2, fetus; Lanes 3 and 4, normal control. Lanes 1 and 3 show the DNA fragments before restriction enzyme treatment, and Lanes 2 and 4 show the DNA fragments after restriction enzyme treatment.

Mentions: The eight exons of the γc chain and surrounding genomic sequences were amplified from genomic DNA as described previously (12). As shown in Fig. 2A, we found a single base substitution (C690T) at exon 5, resulting in an amino acid change at codon 226 (R226C) in the patient. His mother was found to have one mutant and one normal allele, indicating that she was a heterozygous carrier. As the C-to-T substitution predicted the creation of a new AluI restriction endonuclease site, the sequencing results were further confirmed by restriction fragment length polymorphism (RFLP) analysis (Fig. 2B). The patient showed DNA cleavage with AluI (bands of 179 and 133 bp), while the normal control was resistant to AluI. The mother possessed an uncleaved (312 bp) and two smaller bands identical to those in the patient, implying heterozygosity.


X-linked severe combined immunodeficiency syndrome: the first Korean case with gamma c chain gene mutation and subsequent genetic counseling.

Jo EK, Kumaki S, Wei D, Tsuchiya S, Kanegane H, Song CH, Noh HY, Kim YO, Kim SY, Chung HY, Kim YH, Kook H - J. Korean Med. Sci. (2004)

Sequence analysis showing a missense mutation of the common γc chain gene (γc chain) in an X-SCID family. (A) Genomic sequences encompassing a point mutation (C to T) in exon 5 of the γc chain gene from the patient, carrier (mother), and normal control (father) are shown. Arrow, C-to-T transversion. (B) RFLP analysis of the γc chain gene exon 5. Lanes 1 and 2, patient; Lanes 3 and 4, mother; Lanes 5 and 6, normal control. Lanes 1, 3, and 5 show the DNA fragments before restriction enzyme treatment, and Lanes 2, 4, and 6 show the DNA fragments after restriction enzyme treatment. *, Carrier; standard size markers, as indicated on the side. (C) RFLP analysis of amniotic cells. Lanes 1 and 2, fetus; Lanes 3 and 4, normal control. Lanes 1 and 3 show the DNA fragments before restriction enzyme treatment, and Lanes 2 and 4 show the DNA fragments after restriction enzyme treatment.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2822247&req=5

Figure 2: Sequence analysis showing a missense mutation of the common γc chain gene (γc chain) in an X-SCID family. (A) Genomic sequences encompassing a point mutation (C to T) in exon 5 of the γc chain gene from the patient, carrier (mother), and normal control (father) are shown. Arrow, C-to-T transversion. (B) RFLP analysis of the γc chain gene exon 5. Lanes 1 and 2, patient; Lanes 3 and 4, mother; Lanes 5 and 6, normal control. Lanes 1, 3, and 5 show the DNA fragments before restriction enzyme treatment, and Lanes 2, 4, and 6 show the DNA fragments after restriction enzyme treatment. *, Carrier; standard size markers, as indicated on the side. (C) RFLP analysis of amniotic cells. Lanes 1 and 2, fetus; Lanes 3 and 4, normal control. Lanes 1 and 3 show the DNA fragments before restriction enzyme treatment, and Lanes 2 and 4 show the DNA fragments after restriction enzyme treatment.
Mentions: The eight exons of the γc chain and surrounding genomic sequences were amplified from genomic DNA as described previously (12). As shown in Fig. 2A, we found a single base substitution (C690T) at exon 5, resulting in an amino acid change at codon 226 (R226C) in the patient. His mother was found to have one mutant and one normal allele, indicating that she was a heterozygous carrier. As the C-to-T substitution predicted the creation of a new AluI restriction endonuclease site, the sequencing results were further confirmed by restriction fragment length polymorphism (RFLP) analysis (Fig. 2B). The patient showed DNA cleavage with AluI (bands of 179 and 133 bp), while the normal control was resistant to AluI. The mother possessed an uncleaved (312 bp) and two smaller bands identical to those in the patient, implying heterozygosity.

Bottom Line: The patient had a C-to-T point mutation at nucleotide position 690, one of the hot spots, resulting in a single amino acid substitution of cysteine for arginine (R226C), as determined by direct sequencing and PCR-RFLP.Percutaneous umbilical cord blood sampling was performed at the 6-month of gestation in a subsequent pregnancy.As the immunophenotype of the fetus showed an identical pattern, the pregnancy was terminated and genetic analysis of the abortus confirmed recurrence.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology, College of Medicine, Chungnam National University, Daejeon, Korea.

ABSTRACT
X-linked severe combined immunodeficiency (X-SCID) is a rare, life-threatening immune disorder, caused by mutations in the gamma c chain gene, which encodes an essential component of the cytokine receptors for interleukin-2 (IL-2), IL-4, IL-7, IL-9, IL-15, and IL-21. A 13-month-old boy with recurrent infections who had reduced serum immunoglobulin levels and decreased numbers of CD3, CD16/56 cells was evaluated for gamma c chain gene mutation and protein expression. The patient had a C-to-T point mutation at nucleotide position 690, one of the hot spots, resulting in a single amino acid substitution of cysteine for arginine (R226C), as determined by direct sequencing and PCR-RFLP. The patient's mother was a heterozygous carrier. Percutaneous umbilical cord blood sampling was performed at the 6-month of gestation in a subsequent pregnancy. As the immunophenotype of the fetus showed an identical pattern, the pregnancy was terminated and genetic analysis of the abortus confirmed recurrence. This is the first report of the molecular diagnosis of X-SCID in Korea. Genetic analysis of the gamma c chain gene is useful for definite diagnosis and genetic counseling for X-SCID.

Show MeSH
Related in: MedlinePlus