Development of endometrial carcinoma in a patient with leprechaunism (donohue syndrome).

Leprechaunism is a rare autosomal recessive disease that is characterized by severe insulin resistance. This disease is caused by a defective insulin receptor and features abnormal glucose metabolism and retarded intrauterine and postnatal growth. However, there are few reports on the long-term course of leprechaunism. We reported the long-term clinical course and rh-IGF-1 treatment in a patient with leprechaunism. During follow-up her diabetes gradually deteriorated despite of treatment of rh-IGF-1. Furthermore, she developed endometrioid adenocarcinoma at the age of 24 yr. The development of endometrial disease must be carefully followed up in this disease.

A novel PAX4 mutation in a Japanese patient with maturity-onset diabetes of the young.

Maturity-onset diabetes of the young (MODY) is a genetically and clinically heterogeneous type of diabetes mellitus, characterized by early onset (often before 25 years of age) and absence of pancreatic autoimmunity markers. Paired-homeodomain transcription factor 4 (PAX4) functions as a transcriptional repressor and is involved in the differentiation of insulin-secreting ß-cells. Here we identified a novel PAX4 mutation in a Japanese patient with MODY. A 15-year-old, non-obese boy was admitted to our hospital because of polyuria and polydipsia. Laboratory evaluation showed an elevated fasting glucose level; however, islet cell antibodies and glutamic acid decarboxylase antibodies were not detected in the patient's serum. The proband's father had been diagnosed as having type 2 diabetes at age of 30 years. We therefore analyzed several candidate genes of MODY, and identified a novel mutation of a 39-base heterozygous deletion in exon 3 (c.374-412 del39) of PAX4 in the proband and his father. This mutation may cause exon 3 skipping that results in a frameshift, thereby producing a premature stop codon in exon 5. As this mutant PAX4 lacks a part of the homeodomain that is critical for binding to the target gene, this mutant was thought to lose the transcriptional repressor function. As expected, luciferase-reporter assays revealed that the mutant PAX4 could not repress the activities of insulin and glucagon gene promoters, unlike the wild-type PAX4 that repressed the promoter activities. The present study demonstrates that a novel mutation of PAX4 is likely to be associated with diabetes in this Japanese family.

Molecular analysis of the GATA3 gene in five Japanese patients with HDR syndrome.

GATA3 is a member of the GATA family of transcription factors. Heterozygous GATA3 abnormalities are associated with hypoparathyroidism, sensorineural deafness, and renal abnormality (HDR syndrome). However, this triad of symptoms does not occur in all HDR patients and other clinical features may be present in some cases. We report the clinical phenotypes and the molecular analysis of GATA3 in five Japanese HDR patients, including two familial cases. All five patients had hypoparathyroidism and sensorineural deafness, however renal abnormalities were absent in four patients. In addition, two patients with different mutations of GATA3 had female genital tract abnormalities. Sequence analysis of GATA3 demonstrated three novel (R262G, c1063delC and C318) and two reported mutations (c.432insG and c.1051-1G>T). Transient transfection assay using the GATA3 activating reporter system revealed that the transactivating activity of the R262G, c.1063delC, C318S and c.432insG mutants were markedly decreased, indicating that all four mutations are loss-of-function. In conclusion, this study reiterates the clinical variability in HDR syndrome and identifies three novel mutations of GATA3.

Congenital Hypothyroidism Caused by a PAX8 Gene Mutation Manifested as Sodium/Iodide Symporter Gene Defect.

Loss-of-function mutations of the PAX8 gene are considered to mainly cause congenital hypothyroidism (CH) due to thyroid hypoplasia. However, some patients with PAX8 mutation have demonstrated a normal-sized thyroid gland. Here we report a CH patient caused by a PAX8 mutation, which manifested as iodide transport defect (ITD). Hypothyroidism was detected by neonatal screening and L-thyroxine replacement was started immediately. Although (123)I scintigraphy at 5 years of age showed that the thyroid gland was in the normal position and of small size, his iodide trapping was low. The ratio of the saliva/plasma radioactive iodide was low. He did not have goiter; however laboratory findings suggested that he had partial ITD. Gene analyses showed that the sodium/iodide symporter (NIS) gene was normal; instead, a mutation in the PAX8 gene causing R31H substitution was identified. The present report demonstrates that individuals with defective PAX8 can have partial ITD, and thus genetic analysis is useful for differential diagnosis.

Elevated free thyroxine levels detected by a neonatal screening system.

In Sapporo city of Japan, neonatal screening for congenital hypothyroidism has used the measurement of free thyroxine (T4) and thyroid-stimulating hormone (TSH) in the filter-paper blood spot. This system has enabled us to identify hyperthyroxinemic diseases. Filter papers were collected from neonatal infants born at 4-6 d of age and neonates who showed elevated free T4 (>4.0 ng/dL, 4 SD above the mean) were studied. Between January 2000 and December 2006, 83,232 newborns were screened. Eleven infants demonstrated persistent hyperthyroxinemia. One patient with slightly elevated free T4 and normal TSH was diagnosed as having familial dysalbuminemic hyperthyroxinemia (FDH). The other two patients with elevated free T4 without suppressed TSH were considered as having resistance of thyroid hormone (RTH), and analysis of thyroid hormone receptor (TR) beta gene confirmed the diagnosis. The remaining eight patients were diagnosed as having neonatal Graves' disease (NGD). Seven of eight pregnant women were treated with antithyroid drug and thus only one unrecognized NGD during pregnancy was detected by screening. Our screening system enables for early awareness of RTH and FDH. Regarding Graves' disease, the benefit of elevated free T4 screening is small, because most pregnant women with Graves' disease were managed.

Case study of a 15-year-old boy with McCune-Albright syndrome combined with pituitary gigantism: effect of octreotide-long acting release (LAR) and cabergoline therapy.

The use of octreotide-LAR and cabergoline therapy has shown great promise in adults with acromegaly; however, the experience in pediatric patients has rarely been reported. We described a clinical course of a 15-year-old boy of McCune-Albright syndrome (MAS) with pituitary gigantism. At the age of 8 years, a growth hormone (GH) and prolactin (PRL) producing pituitary adenoma was diagnosed at our hospital. He also had multiple fibrous dysplasia, so that he was diagnosed as having MAS. The tumor was partially resected, and GNAS1 gene mutation (R201C) was identified in affected tissues. We introduced octreotide to suppress GH secretion (100 mug 2/day s.c). During therapy with octreotide, IGF-1 and GH levels could not be suppressed and the patient frequently complained of nausea from octreotide treatment. Therefore, the therapy was changed to monthly injections of octreotide-LAR at the age of 12.3 years and was partially effective. However, as defect of left visual field worsened due to progressive left optic canal stenosis, he underwent second neurological decompression of the left optic nerve at 13.4 years of age. After surgery, in addition to octreotide-LAR, cabergoline (0.25 mg twice a month) was started. This regimen normalized serum levels of GH and IGF-1; however, he showed impaired glucose tolerance and gallstones at 15.7 years of age. Therefore, the dose of octreotide-LAR was reduced to 10 mg and the dose of cabergoline increased. This case demonstrated the difficulty of treating pituitary gigantism due to MAS. The use of octreotide-LAR and cabergoline should be considered even in pediatric patients; however, adverse events due to octreotide-LAR must be carefully examined.