Hypoglossal nerve paresis caused by spontaneous dissection of kinked internal carotid artery--case report

A 54-year-old male presented with pure hypoglossal nerve paresis. Angiography and magnetic resonance (MR) imaging showed the characteristic findings of left internal carotid artery (ICA) dissection. He received aspirin and his symptoms gradually disappeared. Repeat angiography and MR imaging showed that the lesion had completely disappeared. This case supports the hypothesis that hypoglossal nerve paresis is due to nerve stretching and compression by intramural hematoma of the dissected ipsilateral ICA, and severe tortuosity of the ICA may be a related phenomenon.

[Clinical effects of sodium ozagrel and urokinase in patients with acute cerebral infarction in the territory of the internal carotid artery]

In this study, the clinical effects were compared between a thromboxane synthetase inhibitor (sodium ozagrel) and a thrombolytic agent (urokinase) in patients with acute cerebral infarction. The subjects consisted of 598 patients admitted on the day of the onset of the cerebral infarction in the territory of the internal carotid artery who showed a low density area on CT images within 5 days. Of these patients, 300 were treated with sodium ozagrel and classified as Group Oz, while the remaining 298 were treated with urokinase and classified as Group Ur. The results were as follows: 1. In group Oz, complete recovery of motor impairment was seen in 209 (69.7%) patients. Complete recovery within 3 weeks after onset was seen in 186 (62.0%) patients. In group Ur, complete recovery of motor impairment was seen in 175 (58.7%) patients. Complete recovery within 3 weeks after onset was seen in 120 (40.3%) patients. Therefore, a higher incidence of complete recovery of the motor impairment was noted in group Oz [p < 0.001: chi 2 test]. Similarly, complete recovery within 3 weeks after onset was more frequent in group Oz [p < 0.001: chi 2 test]. 2. In group Oz, complete recovery was made contribution statistically by Anosognosia (Ag) and unilateral neglect (UN) on admission [multivariate analysis: p < 0.01]. In group Ur, complete recovery was made contribution statistically by Ag (p < 0.01), UN (p < 0.01) and aphasia (p < 0.05). 3. Progressive stroke was observed in 29 (9.5%) patients in the group Oz and in 71 (23.0%) patients in group Ur. There was a higher incidence of progressive stroke in group Ur [p < 0.001: chi 2 test] 4. All patients with progressive stroke had initial evidence of deterioration of neurological deficits within 6 days after the onset in group Oz, and within 5 days after the onset in group Ur. The maximal period from the beginning to the end of the deterioration of neurological deficit was 7 days. 5. In group Oz, progressive stroke was only seen in 29 (29.9%) of the patients who were admitted with motor disturbances and unilateral neglect. In group Ur, progressive stroke was seen in 8 (4.3%) of the 187 patients with motor disturbances without higher cortical dysfunction, in 17 (47.2%) of the 36 patients with motor disturbances and higher cortical dysfunction without unilateral neglect and was seen in 46 (61.3%) of the patients with motor disturbances and unilateral neglect. 6. Hemorrhagic infarction was observed in 14 (4.6%) patients in group Oz and in 31 (10.0%) patients in group Ur. There was a higher incidence of hemorrhagic infarction in group Ur [p < 0.001: chi 2 test]. 7. In group Oz, there was a higher incidence of hemorrhagic infarction among patients with atrial fibrillation (Af) on the ECG [p < 0.001: chi 2 test]. Similarly, in group Ur, hemorrhagic infarction was more frequent among patients with atrial fibrillation (Af) on the ECG [p < 0.001: chi 2 test]. Therefore, sodium ozagrel was clinically more efficient and safer than urokinase in patients with acute cerebral infarction.

Increased epinephrine-induced cAMP response in severely diabetic BB/W rat liver

The effect of prolonged diabetes on epinephrine-induced adenosine 3',5'-monophosphate (cAMP) response in the liver was examined in diabetes-prone BB/W rats. Basal and 1 microM epinephrine-induced cAMP release from isolated perfused liver was similar in non-diabetic and diabetic BB/W rats with preserved adipose tissue. In adipose tissue-absent diabetic rats losing intra- and retro-peritoneal adipose tissue completely, both basal and 1 microM epinephrine-induced cAMP release from the liver were enhanced (P<0.01, each case). Plasma epinephrine and norepinephrine were similar in non-diabetic, adipose tissue-preserved and -absent diabetic BB/W rats. The plasma free thyroxine level was similar in non-diabetic and adipose tissue-preserved diabetic BB/W rats, but was lower in adipose tissue-absent diabetic BB/W rats than in non-diabetic rats (P<0.01), but the frequency of lymphocytic thyroiditis was similar in these three groups, although plasma corticosterone was lower in adipose tissue-preserved diabetic BB/W rats (P<0.05) and the lowest in adipose tissue-absent diabetic BB/W rats (P<0.01). Lymphocytic infiltration was not observed in the adrenal or pituitary glands in any group. Plasma total protein and albumin were low in adipose tissue-absent diabetic BB/W rats (P<0.01, each case). In adipose tissue-absent diabetic BB/W rats, liver dysfunction and hepatomegaly, but no apparent histological change in the liver, were observed. Plasma glucose was higher (P<0.01) and plasma insulin lower (P<0.05) in adipose tissue-absent diabetic BB/W rats than in adipose tissue-preserved diabetic BB/W rats. In conclusion, epinephrine-induced cAMP response in the liver was enhanced only in adipose tissue-absent diabetic BB/W rats. Denervation supersensitivity was not likely to be responsible for the enhanced beta-adrenergic response. The observed reductions in plasma thyroxine and corticosterone seemed to result from severe diabetes. Although the severity of diabetes can vary continuously, severe diabetes with loss of adipose tissue appeared to cause significant changes in the metabolism and enhanced beta-adrenergic response in the liver.

Case report: interferon induced coma in Sheehan's syndrome

A 54-year-old woman who was being treated with 10 million units (mu) of natural interferon (IFN)-alpha per day for chronic active hepatitis C at a local clinic, developed coma on the fourth day of treatment. On admission to Yamagata University Hospital, she was still in a state of semicoma with severe hyponatraemia (122 mEq/L) and hypochloraemia (89 mEq/L). After the administration of electrolytes, her condition improved remarkably. Endocrinological loading tests showed a hypofunction of the anterior pituitary gland. In consideration of these results, and her past experiences of haemorrhage during childbirth and subsequent amenorrhoea, we diagnosed her illness as a coma as a result of Sheehan's syndrome which had become overt during IFN therapy. She recovered completely after treatment with hydrocortisone and l-thyroxine.

A novel missense mutation in exon 4 of the human coproporphyrinogen oxidase gene in two patients with hereditary coproporphyria

Hereditary coproporphyria (HCP) is an autosomal dominant disease characterized by a deficiency of coproporphyrinogen oxidase. To date, four mutations of the gene have been reported. We report here another mutation in two Japanese families with HCP, which was revealed by analysis of polymerase chain reaction (PCR)-amplified DNA fragments of the gene by a direct-sequencing method. A point mutation, G to A, was found in exon 4 of the gene at position 538 of the cDNA from the reported putative translation initiation codon ATG. This mutation results in a glycine to arginine substitution at amino acid 180. Two carriers in the family were successfully diagnosed by detecting the mutation using restriction analysis of the PCR products.

Identification of a human cDNA homologue to the Drosophila translocation protein 1 (Dtrp1)

In yeast, several integral membrane proteins such as Sec61p, Sec62p and Sec63p have been reported as the components involved in protein translocation across and into the endoplasmic reticulum (ER) membrane. Among them, the homologues of Sec61p have been found both in bacterias and mammals, whereas those of Sec62p or Sec63p have not. So, Sec61p seem to be the evolutionary conserved component, while Sec62p and Sec63p may not. To date, no homologues of Sec62p have been found in mammals yet. Here, we report a novel human cDNA, HTP1 (for human translocation protein 1), that encodes a protein of 399 amino acids that is 36.3% identical (64.6% similar) to Drosophila homologue of Sec62p, Drosophila translocation protein 1 (Dtrpl). Northern blot analysis showed two HTP1 transcripts of about 2.8 and 5.5 kb, which were expressed concomitantly in various human tissues such as heart, brain, placenta, liver and pancreas.

Functional localization of glucose transporter 2 in rat liver

Heterogeneity of zonal hepatocytes is important to elicit specific liver function. We investigated the distribution of glucose transporter 2 (GLUT-2) in normal rat liver by immunostaining and Northern blot analysis. GLUT-2 stained by immunohistochemistry was distributed predominantly in the periportal hepatocytes and gradually thinned towards the perivenous zone. Ultrastructural immunostaining of GLUT-2 showed that it was localized on microvilli of the sinusoidal plasma membrane of hepatocytes but not on the basolateral plasma membrane. Consistent with the distribution of GLUT-2 protein, the level of GLUT-2 mRNA in periportal hepatocytes was 1.9-fold higher than in perivenous hepatocytes selectively isolated by the differential isolation technique. In addition, the mRNA level of phosphoenolpyruvate carboxykinase, one of the key enzymes of gluconeogenesis, was also twofold higher in the periportal hepatocytes. These results suggest that GLUT-2 contributes to the functional difference between periportal and perivenous hepatocytes in glucose metabolism of the liver.

Family study of acute intermittent porphyria and hereditary coproporphyria in Niigata and Akita Prefectures, Japan

Simple screening tests, urinary porphobilinogen (PBG) for acute intermittent porphyria (AIP) and fecal coproporphyrin for hereditary coproporphyria (HCP), were performed in a family study of AIP and HCP. Urinary PBG was positive in 93 of 211 members of 10 AIP families, but was negative in 568 of 572 controls. Fecal coproporphyrin was positive in 54 of 108 members of 10 HCP families, but was negative in 188 controls. A dominant inheritance was assumed by a chi-square test and Weinberg segregation ratio. Worsening factors around puberty were suggested by the onset age and cumulative percentage of genetically loaded cases. Sex-related expression of symptoms was also inferred by a higher incidence of both porphyrias in females than in males. Fitness and penetrance of both porphyrias were good. An l-triiodothyronine loading test was the most useful for the detection of masked carriers of AIP. In conclusion, AIP and HCP in Japan show a dominant inheritance with sex-related metabolic and clinical manifestations.

Hyper-adrenocorticotropinemia in a patient with Addison's disease after treatment with corticosteroids

A 40-year-old man with Addison's disease due to adrenal tuberculosis retained high levels of adrenocorticotropic hormone (ACTH) after conventional hydrocortisone replacement. Plasma ACTH levels were completely suppressed by usual replacement with hydrocortisone (20 mg at 8:00 and 10 mg at 21:00) but rebounded to abnormally high levels the following morning. Administration of 2 mg or 8 mg of dexamethasone suppressed ACTH and cortisol. Magnetic resonance imaging of the brain showed a low-intensity lesion of the pituitary gland. Pituitary hyperplasia or microadenoma with preserved regulation of ACTH was considered to be the cause of the high plasma ACTH levels. The combination of hydrocortisone and dexamethasone reduced plasma ACTH levels.

Intracerebroventricular injection of methylatropine suppresses insulin response to oral glucose load in rats

Hepatic glucoreceptor-vagal afferent inputs to the central nervous system and pancreatic vagal efferent stimuli are important for insulin secretion. In the present study, we examined the effect of intracerebroventricular (i.c.v.) injection of atropine methyl bromide (methylatropine) on the insulin response following glucose ingestion in rats. When rats were injected with methylatropine i.c.v., the plasma glucose concentration increased, the insulin response reduced, and glucagon-like peptide-1 (7-36) amide (tGLP-1) was unchanged following an oral glucose load, compared with the controls. The plasma insulin response following an intravenous glucose load was not affected by i.c.v. or intraperitoneal injection of methylatropine. A transient increase in plasma insulin after selective hepatic vagotomy was inhibited by i.c.v. injection of methylatropine. Arterial blood pressure or pulse rate was not changed by i.c.v. injection of methylatropine. These results show that the central nervous system plays an important role in the vagal control of the insulin response to glucose ingestion. In rats, for the insulin response soon after glucose ingestion (early phase insulin response), direct neural control (hepatic vagal afferent-central nervous system-pancreatic vagal efferent) of the islet B cells seems more important than the intestinal insulinotropic hormone, tGLP-1.

A nonsense mutation of the ceruloplasmin gene in hereditary ceruloplasmin deficiency with diabetes mellitus

A novel mutation of the ceruloplasmin (Cp) gene was found in a patient with hereditary ceruloplasmin deficiency (HCD) with diabetes mellitus (DM). The patient had been treated for DM for about 13 years, and then his illness was diagnosed as HCD. One year later, he was found dead in his home. A decrease in insulin-immunostained cells was observed in the islets of the patient's pancreas tissue, which accounted for his DM. The polymerase chain reaction (PCR)-direct sequencing analysis of the Cp gene of his daughter revealed a novel point mutation, G to A, at nucleotide 2630 in exon 15. This mutation changes the Trp858 codon (TGG) to a stop codon (TAG) (nonsense mutation). PCR-restriction analysis for the mutation revealed that the patient as well as his daughter was a heterozygote for the mutation, indicating that the patient was a compound heterozygote.

Dinucleotide repeat polymorphism in the human ceruloplasmin gene

We have identified a GT dinucleotide repeat polymorphism in intron 14 of the human ceruloplasmin gene. Observed heterozygosity for the polymorphism is 0.84.

Response of truncated glucagon-like peptide-1 and gastric inhibitory polypeptide to glucose ingestion in non-insulin dependent diabetes mellitus. Effect of sulfonylurea therapy

Gastric inhibitory polypeptide (tGIP) and truncated glucagon like peptide-1 (GLP-1) are potent gastrointestinal insulinotropic factors (incretin), are most released after a meal or ingestion of glucose in man and animals. To investigate whether sulfonylurea (SU) affects the secretion of incretin, the modulation of plasma GIP and tGLP-1 levels following glucose ingestion in non-insulin-dependent diabetic type 2 patients with or without SU therapy was studied. A 75-G oral glucose tolerance test (OGTT) was carried out on 9 healthy subjects (controls) and 18 patients with non-obese type 2, 9 of whom were treated by diet alone (NIDDM-diet) and the other 9 with SU (glibenclamide 2.5 mg or gliclazide 40 mg) once a day (NIDDM-SU). Plasma GIP was measured by radioimmunoassay (RIA) with R65 antibody, and GLP-1 was measured by RIA with N-terminal-directed antiserum R1043 (GLP-1NT) and C-terminal-directed antiserum R2337 (GLP-1CT). Following OGTT, plasma glucose, GIP, GLP-1NT, and GLP-1CT in type 2 patients increased more markedly than in controls, despite the lower response of insulin. However, there were no significant differences in plasma levels of these peptides between the NIDDM-diet and NIDDM-SU groups. Therefore, it is unlikely that SU is involved in the high response of GIP and GLP-1s to OGTT in type 2 patients.

Insulin-like growth factor I resistance in peripheral tissue but not in liver in streptozotocin-induced diabetic rats

The metabolic effect of recombinant human insulin-like growth factor I (IGF-I) was investigated by the glucose clamp technique in normal rats and streptozotocin-induced diabetic rats, a model of insulin-dependent diabetes mellitus (IDDM), and compared with that of insulin. Glucose uptake by peripheral tissues was stimulated by intravenous administration of IGF-I at rates of from 0.369 to 3.690 nmol/kg/min in a dose dependent manner, with a potency of 1/52 that of insulin estimated on the basis of the ED50 molar ratio in normal rats. In streptozotocin-induced diabetic rats, the maximum effects of IGF-I and insulin were reduced to 72% and 70% of those in normal rats, respectively, indicating the presence of both IGF-I and insulin resistance. Hepatic glucose output in normal rats was suppressed by IGF-I in a dose dependent manner with a weaker potency of 1/99 that of insulin assessed on the basis of the ED50 values. In streptozotocin-induced diabetic rats, a dose-response curve of the suppressive effect of insulin on hepatic glucose output shifted to the right, indicating the presence of hepatic insulin resistance, but a leftward shifting of the suppressive effect of IGF-I on hepatic glucose output was observed. We concluded that the IGF-I effect on peripheral tissue was decreased but that on the liver was rather increased in streptozotocin-induced diabetic rats, in contrast to the resistance of both peripheral tissues and liver to insulin.

A point mutation, C to T, in exon 8 of the porphobilinogen deaminase gene in a Japanese family with acute intermittent porphyria

Acute intermittent porphyria (AIP) is an autosomal dominant disease characterized by a deficiency of porphobilinogen deaminase (PBGD). To date, only two mutations have been reported in Japanese patients. We report here another mutation of the gene in a Japanese patient. Analysis of the PCR amplified DNA fragments of the gene by direct-sequencing method revealed the gene abnormality responsible for the disease. The mutation found was a point mutation, C to T, in exon 8 of the gene at position 346 of the housekeeping cDNA from the translation codon ATG. This mutation resulted in an Arg116 to Trp substitution. Four carriers in the family were successfully diagnosed by detecting the mutation using restriction analysis of PCR products.

Fine structure of the human ceruloplasmin gene

We characterized the genomic region corresponding to the human ceruloplasmin cDNA previously reported. Using PCR-direct sequencing methods, we determined precise intron/exon boundaries and intron-exon composition of the gene in the region. The gene region spanned about 50 kb and was composed of 19 exons and 18 introns. The lengths of exons and introns range from 107 to over 267 bp and from 0.44 to 10.0 kb, respectively. The translation initiation codon and the termination codon were located in exons 1 and 19, respectively. The nucleotide sequences of the introns were also determined in the region around the intron/exon boundaries for 24-220 bp. All the sequences around the intron/exon boundaries were consistent with the 5' and 3' consensus sequences for splice junctions of transcribed genes. Putative lariat sequences were identified between -17 and -42 nucleotides from the 3' splice junction for all 18 introns.

Intracerebroventricular administration of somatostatin octapeptide counteracts the hormonal and metabolic responses to stress in normal and diabetic dogs

Intracerebroventricular (ICV) injection of carbachol elicits hormonal and metabolic responses similar to moderate stress. In normal dogs, ICV carbachol stimulated marked counterregulatory hormone release, but altered plasma glucose only marginally because the marked increment in glucose production (Ra) was almost matched by the increment of utilization (Rd), even though plasma insulin was unchanged. In alloxan-diabetic dogs, Rd did not match Ra and plasma glucose increased substantially. Since somatostatin octapeptide (ODT8-SS) inhibits some sympathetic mechanisms of the stress response, we explored the extent to which ODT8-SS can alleviate the counterregulatory responses to stress induced by carbachol, and particularly whether it can restore glycemic control in diabetes. ODT8-SS (20 nmol) was ICV-injected (1) in normal dogs (n = 5), and (2) prior to ICV carbachol before (n = 7) and after (n = 6) the induction of alloxan-diabetes. ODT8-SS did not affect basal values, but when administered before ICV carbachol there were no significant increments in plasma epinephrine, cortisol, arginine vasopressin (AVP), insulin, glucose, or lactate. There were significant increases in norepinephrine, glucagon, Ra, Rd, and the glucose metabolic clearance rate (MCR), although they were much smaller than seen previously with ICV carbachol alone. After induction of alloxan-diabetes, Rd and MCR did not change with ICV ODT8-SS and carbachol as in normal dogs, but norepinephrine, epinephrine, glucagon, lactate, plasma glucose, and Ra increased, although with the exception of glucagon these increases were much smaller than seen previously with ICV carbachol alone. ODT8-SS administered before ICV carbachol in normal or diabetic animals resulted in increased free fatty acid (FFA) levels. The increases in glycerol were less than and those in FFA greater than seen previously with ICV carbachol alone. Since ODT8-SS does not alter basal counterregulatory hormone release but suppresses the release during stress, this is a useful probe to analyze some of the metabolic responses to stress. When the response to carbachol from our previous report is compared with the responses to carbachol + ODT8-SS, it is indicated that the stress-related increase in Ra was consistent with stimulation of the sympathetic nervous system, whereas increased Rd is related to an unknown stress-related neuroendocrine mechanism that requires a permissive effect of insulin, since it was not seen in the frankly diabetic animals. We hypothesize that the stress-induced increase in Rd occurs not only in muscle but also in adipocytes, and that the somatostatin-induced attenuation of Rd decreased FFA re-esterification and consequently markedly increased stress-induced FFA release.(ABSTRACT TRUNCATED AT 400 WORDS)

Gliclazide directly suppresses arginine-induced glucagon secretion

To clarify whether the effect of sulfonylurea on glucagon secretion is directly on the pancreatic A cell, we examined changes produced by gliclazide in glucagon (IRG), insulin (IRI) and somatostatin (IRS) release from the isolated perfused rat pancreas. Under 5 mM glucose infusion, IRI and IRS were increased by gliclazide in a dose-dependent manner, but IRG was unchanged. When 20 mM arginine was infused to stimulate glucagon secretion, both IRI and IRG increased markedly in a biphasic fashion and IRS increased slightly. The administration of gliclazide at the time of second phase response of IRG, IRI and IRS increased further and IRG decreased at every dose used. Insulin administration to the control and streptozotocin-treated rat pancreas did not change arginine-induced IRG secretion. Gliclazide-induced glucagon suppression was also observed in streptozotocin-diabetic rat pancreas. The amount of administered somatostatin required for inhibiting glucagon secretion was higher than the maximal level obtained from endogenous secretion of somatostatin after gliclazide. Neither cysteamine treatment alone (somatostatin-depleted) nor combined with streptozotocin-treatment (combined depletion of somatostatin and insulin) changed gliclazide-induced glucagon suppression. Thus, it is concluded that suppression of glucagon is induced by sulfonylurea itself.

Catecholamine-induced cAMP response in streptozotocin-induced diabetic rat liver

The effect of prolonged diabetic state on catecholamine-induced adenosine 3',5'-monophosphate (cAMP) response in the rat liver was examined using isolated liver perfusion. Epinephrine- or isoproterenol-induced cAMP production was enhanced (10-fold of the control) in the liver from extremely emaciated (intraperitoneal adipose tissue was absent completely) diabetic rats 4 weeks after streptozotocin-injection kept without insulin, but not from adipose tissue-present diabetic rats. Glucagon-induced cAMP production was decreased in the diabetic rat liver 4 weeks after streptozotocin regardless of the presence or absence of adipose tissue. Secretin-induced cAMP production was also decreased in the adipose tissue-absent diabetic rat liver. Plasma levels of glucose or insulin were not different between adipose tissue-present and -absent diabetic rats. Liver dysfunction (elevated AST and ALT levels) was observed 1 week after streptozotocin-injection, and worsened at 4 weeks. Forskolin-induced production of cAMP, and oxymetazoline (an alpha 2-adrenergic agonist)-induced suppression of it were not different among the control, newly diabetic (1 week after streptozotocin-injection), and the adipose tissue-absent diabetic rat liver.

IN CONCLUSION

1) enhanced beta-adrenergic, and decreased glucagon- or secretin-induced cAMP production seems to be caused by different mechanisms; 2) the prolonged severe diabetic state losing adipose tissue may cause a considerable change in metabolism and the characteristics of hepatocyte, and lead to enhanced beta-adrenergic cAMP production.

Acute intermittent porphyria caused by a single base insertion of C in exon 15 of the porphobilinogen deaminase gene that results in a frame shift and premature stopping of translation

A single base insertion of C in exon 15 of the porphobilinogen deaminase (PBG-D) gene was observed in a patient with acute intermittent porphyria (AIP) by polymerase chain reaction (PCR)-direct sequencing analysis. The insertion locates between positions -22 and -21 from the translation termination codon TAA, causes a frame shift, and results in a stop codon located 4 codons downstream from the insertion (premature stopping of translation). The mutation generates an MspI recognition site, which can be used, in turn, to detect the mutant allele. Analysis of the cDNA fragments amplified by PCR revealed the existence of the abnormal PBG-D mRNA from the mutant allele in the patient.

Stimulation of truncated glucagon-like peptide-1 release from the isolated perfused canine ileum by glucose absorption

To elucidate whether glucose absorption is necessary for oral glucose-induced truncated glucagon-like peptide-1 (tGLP-1) release, we examined tGLP-1 release by several stimulants from isolated perfused canine ileum. Glucose and nonabsorbable sugars, sucrose and 2-deoxyglucose (2DG), were intraluminally administrated. Following gel filtration of the perfusate after glucose ingestion, the main component of GLP-1 in the eluate is tGLP-1. Both glucose and tGLP-1 in the effluents increased after the intraluminal administration of 5% glucose, but not by that of sucrose or 2DG. Glucose absorption is more important than contact of glucose with ileal epithelium to stimulate tGLP-1 release.

Acute intermittent porphyria caused by a G to C mutation in exon 12 of the porphobilinogen deaminase gene that results in exon skipping

Genomic DNA from a patient with acute intermittent porphyria were analyzed by the polymerase chain reaction (PCR)-direct sequencing method. The patient was heterozygote for a point mutation G to C at the last position of exon 12 of the porphobilinogen deaminase (PBG-D) gene. Analysis of the cDNA fragments amplified by PCR revealed that the patient has the abnormal PBG-D mRNA, which does not have exon 12 and exists in an approximately equal amount to the normal mRNA.