Novel mutation of methylmalonyl-CoA mutase gene in a Thai infant with methylmalonic acidemia (mut0).

Isolated methylmalonic acidemia is found in patients with mutations in the MUT gene causing partial methylmalonyl CoA mutase deficiency, mut-, or complete methylmalonyl CoA mutase deficiency, mut0. Most mut0 patients have an earlier and more severe presentation than the other groups such as mut- and cbl defect. We report a 6-month-old Thai male presenting with wide-anion gap metabolic acidosis after acute lower respiratory infection. Urine organic acids analysis demonstrated excretions of methylmalonic acid and methylcitrate, consistent with methylmalonic acidemia. He was then started on low protein diet with an appropriate metabolic formula, L-carnitine (100 mg/kg/day), and oral vitamin B12 (1 mg/day). He had only one single metabolic episode at 2 years of age. At present, he is doing well with normal growth and development. His methylmalonyl-CoA mutase activity was undetectable compatible with mut0. He was found to be homozygous for a novel IVS11-2A>G mutation causing two aberrantly spliced transcripts. The identified mutation and enzyme activity of this patient should cause severe phenotype, although, our patient has milder clinical manifestations. Therefore we hypothesize that there are other factors that may determine the clinical phenotype of mutase deficiency in the present case.

Factors influencing development of Down syndrome children in the first three years of life: Siriraj experience.

OBJECTIVE: To analyze factors influencing development of Down syndrome children in the first three years of life. MATERIAL AND METHOD: A cross-sectional study was conducted in 100 Down syndrome (DS) children attending at the Genetics clinic, Department of Pediatrics, Siriraj Hospital between January 2002 and December 2005. All individuals were three to six years of age. The data was collected from January to December 2006, including general information and factors on the child and their families. The child developmental quotient (DQ) was evaluated by Capute Scales Cognitive Adaptive Test/Clinical Linguistic & Auditory Milestones Scale (CAT/CLAMS) at three years of age. Data were analyzed by descriptive statistic and multiple linear regression with the significant level at p-value < 0. 05. RESULTS: The mean development quotient (DQ) was 63.78 +/- 11.25 (range 32-91) with the majority being mild developmental delay. The child and family factors contributing to developmental quotient (DQ) outcome were birthplace, congenital heart disease, age at the first genetic counseling, regular follow-up in the Genetics clinic, age at the first early stimulation program/speech training program, parental education/occupation, and family income. Only family income and age at the first speech-training program were found to be independently associated with developmental quotient (DQ) at the age of three years (p-value < 0.05). CONCLUSION: Down syndrome is the most common genetic cause of mental retardation. Various factors contribute to developmental quotient (DQ) outcome but the most important factors are family income and age at the first speech-training program. Therefore, Down syndrome children with the above factors should be followed-up and monitored closely for the optimal long-term outcome.

Neural tube defects at Siriraj Hospital, Bangkok, Thailand--10 years review (1990-1999).

OBJECTIVES: Neural tube defects (NTDs), (including anencephaly, meningomyelocele and encephalocele), are among the most common birth defects, with high associated mortality and morbidity. NTDs occur in 1-5 per 1,000 births, with marked geographic and ethnic variations. However, there are few data concerning the incidence, associated anomalies, treatment and outcome of NTDs in Thailand. The objective of this study is to analyze data on NTD cases from 1990-1999 at Siriraj Hospital, a hospital with 18,000-20,000 deliveries annually. MATERIAL AND METHOD: A retrospective chart review of patients with NTDs who were born at or referred to Siriraj Hospital 1990-1999 was performed. RESULTS: During the 10 year period we examined, there were 115 patients with NTDs treated in the Department of Pediatrics as well as in other Departments at Siriraj Hospital. The incidence of NTD is 0.67 per 1,000 births. The sex distribution was equal among NTD cases, 55 (48%) females, 59 (51%) males and one (1%) unidentified sex. Isolated NTDs accounted for 105 (91%) cases, and 10 (8.7%) had at least 1 other structural anomaly such as cleft lip/palate, imperforate anus, amniotic band sequence, or ambiguous genitalia. Among all NTD cases, there were 55 (48%) with myelomeningocele, 45 (39%) with anencephaly, and 14 (12%) with encephalocele. Seventeen (15%) cases died; among these, 7 (41% of deaths) died in utero, 8 (47% of deaths) died in the early neonatal period, and 2 (12%) died after 1 year of age. Regarding treatment, 95 surgical corrections, 47 excisions and repairs, 45 excisions and VP shunts, 1 laminectomy and 2 club feet corrections were performed. CONCLUSIONS: In this hospital-based study of 115 patients with NTD, we found an incidence of 0.67/1000 births; however, as this was a hospital-based study, the community incidence is likely higher. Most cases were isolated NTDs, and almost half of NTDs were meningomyelocele. There was a high rate of mortality. Further studies are warranted to better elucidate the health burden from NTDs in Thailand. Public health interventions aimed at increasing the periconceptional consumption of folic acid should be implemented or enhanced to reduce the incidence of NTDs in Thailand.

Fetal warfarin syndrome.

Fetuses exposed to Warfarin in the first trimester of pregnancy have an increased risk of embryopathy which consists of nasal hypoplasia and stippled epiphyses, known as fetal warfarin syndrome or warfarin embryopathy. We herein report a first case of an infant with fetal warfarin syndrome in Thailand. The patient was an offspring of a 34-year-old mother with history of SLE and arterial embolism for several years. She had an unplanned pregnancy while taking warfarin. The patient developed difficulty breathing in the first few hours after birth from severe nasal hypoplasia. He also had short limbs, brachydactyly, nail hypoplasia, and calcifications in the epiphyseal regions of humeri, femora and vertebrae radiographically. The patient eventually died from respiratory failure at 6 months of age.

The molecular basis of mucopolysaccharidosis type I in two Thai patients.

Two Thai patients diagnosed with Hurler syndrome (mucopolysaccharidosis type 1, MPS I) were found to have no detectable alpha-iduronidase (E.C. 3.2.1.76) activity in leukocytes, while normal Thai children all had significant activity, with a mean of 135 +/- 30 nmol/mg/18h. One patient was heterozygous for A75T (311G>A) and S633L (1986C>T) mutation, previously reported to cause MPS I, together with 9 other heterozygous polymorphisms also found in normal controls. The other patient had the previously described frameshift mutation 252insert C and a new nonsense mutation E299X (983G>T).

Retrospective study of patients with suspected inborn errors of metabolism at Siriraj Hospital, Bangkok, Thailand (1997-2001).

INTRODUCTION: This retrospective clinical study was carried out on patients with suspected inborn errors of metabolism (IEM) at Siriraj Hospital during 1997-2001. The authors investigated 114 patients by quantitative plasma amino acid analysis. OBJECTIVE: The objective of this study was to collect and analyze epidemiologic and specific clinical data of IEM, especially in small-molecule diseases. MATERIAL AND METHOD: All patients were categorized into 2 major groups. 1) positive diagnoses for IEM 2) negative diagnoses for IEM. The two groups were investigated, studied including statistical analysis. RESULTS: The authors found that most IEM ascertained through plasma amino acid analysis were small-molecule diseases (74.3%) and amino acid disorders consisted of the most frequent disorders. The presented data demonstrated that the ratio of positive diagnoses to all patients studied was 1:8. Epidemiological data showed there were more male than female patients. Onset of diseases occurred predominantly during the first month of age, and was rarely found after 3 years of age. There were histories of consanguinity in half of the IEM patients. The most common presenting symptom was acute metabolic encephalopathy and specific signs for small-molecule disorders included hepatomegaly, unusual urine odor, acidosis, hyperammonemia, alteration of consciousness, and ketosis/ketonuria. These signs or symptoms indicated further metabolic investigations. CONCLUSION: Comparison of the data from Thailand with other countries showed both similarities and differences to the Caucasian population. Thus, further studies in IEM are much needed for the Thai population.

Argininosuccinate synthetase deficiency: mutation analysis in 3 Thai patients.

Remarkable improvements in public health, nutrition, hygiene, and availability of medical services in the last 20 years have significantly reduced infant and childhood mortality in Thailand. Therefore, many rare and previously unidentified genetic disorders, which, in the past, usually led to the death of affected infants before a definitive diagnosis, have now been increasingly recognized. Recently, we identified three unrelated patients from Thailand who suffered from citrullinemia, one of five inherited types of urea cycle disorders. All were diagnosed within their first few weeks of life. Biochemical analyses, including plasma amino acid and urine organic acid profiles, are consistent with argininosuccinate synthetase (ASS) deficiency. Extensive mutation study by direct genomic sequencing of ASS demonstrated a homozygous G117S mutation in one patient and homozygous R363W mutations in the other two families.

Molecular markers for diagnosis of Prader-Willi syndrome in thai patients by fish.

Paternal microdeletion of chromosome 15 at q11-q13 has been reported in 75% of Prader-Willi syndrome (PWS) patients in western countries. Diagnosis of PWS in Thailand is mainly based on clinical observation and, in some cases, confirmed by conventional cytogenetic analysis. Loss of a tiny segment in this region (microdeletion) has made it difficult to discriminate from the normal karyotype. An attempt to solve this problem has been made by using a high resolution chromosome culture. However, this method is a tedious and time-consuming technique which is suitable for only experienced cytogeneticists. We report molecular cytogenetic analysis for PWS in Thai patients using FISH in addition to standard GTG- banding chromosome analysis. Nine Thai patients clinically diagnosed or with a suspicion of PWS were investigated. The FISH probes consist of the region-specific probes (SNRPN or D15S10 probe) and two chromosome 15-specific control probes (D15Z1 centromeric and PML chromosome 15 long arm probe). Bright field and FISH programs of an automatic karyotyper were applied to facilitate the efficiency of the chromosome analysis. We found that 2 out of 9 patients showed a deletion at 15q11-q13 region by standard GTG chromosome analysis while 4 out of 9 patients showed a delation in this region by FISH. Consistent losing of SNRPN and D15S10 signals in FISH was observed in these patients. This forty-four per cent deletion is considerably lower than those reported from western countries. We propose that DNA methylation at SNRPN promoter as well as structural abnormalities in other chromosome regions might also play a role in the etiology of this disorder in Thais, which should be investigated further.

Cervical cord decompression and posterior cervical immobilization following anterior C1-C2 subluxation in a patient with MPS type IV (morquio syndrome) : A team approach.

We report a 23 month old gril who presented with right hemiparesis after falling for 6 months. She was also diagnosed with mucopolysaccharidosis type IV (Morquio syndrome) with C1-C2 subluxation. Anesthesia was uneventful after inhalation induction, manual in-line stabilization, intubation, external fixation of the cervical spine, followed by prone position and manual assisted ventilation. Postoperative pain was relieved using a tramadol infusion.

Prenatal genetic screening for Down syndrome and open neural tube defects using maternal serum markers in Thai pregnant women.

Maternal serum screening has gained widespread acceptance as a major prenatal screening tool for chromosomal abnormalities in the US and Europe since Merkatz et al described an association between low maternal serum alpha fetoprotein (AFP) levels and increased risk for trisomy 21 in 1984. In 1988, Wald et al proposed a screening program based on maternal age in combination with three biochemical markers--AFP, hCG and unconjugated estriol. This study from January 1996--September 2002 included 1,793 pregnant women (between 14-22 weeks gestation) which were divided into 2 groups--1,083 women > 35 years (60.40%) and 710 women < 35 years (39.60%). A second trimester risk for trisomy 21 > 1 : 270 was considered a positive screen and genetic counseling to discuss risks and benefits of amniocentesis was offered. This study had 1,376 cases (76.7%) with negative screening (not increased risk for DS and NTD), 21 (1.2%) with negative screening (not increased risk for DS only) ; 292 (16.3%) with increased risk for DS; 5 cases (0.3%) with increased risk for DS and elevated AFP; 19 cases (1.1%) with elevated AFP; 33 cases (1.8%) with previous DS only; and 9 cases (0.5%) with previous NTD only. Two percent (2.1%) of the results could not be interpreted either because the test was done too early, too late or were grand multiple pregnancies. This study demonstrated that multiple marker screening offers another option for older women who traditionally have all been considered candidates for amniocentesis.

Urea cycle disorders in Thai infants: a report of 5 cases.

Urea Cycle Disorders (UCD) is an inborn error of urea synthesis in which ammonium and other nitrogenous precursors of urea accumulate leading to episodic coma and a high mortality rate. Therapy with peritoneal dialysis, essential amino acids or their nitrogen-free analogues has increased survival. The authors report 5 cases of urea cycle disorders, all of whom developed and were rescued from hyperammonemic coma. However, the eventual outcome was quite variable. Argininosuccinate lyase deficiency (ALD) Case 1. A 2 month old male infant, a product of a consanguineous marriage (Suphanburi province); developed poor feeding on day 7, lethargy, convulsion, hepatomegaly and respiratory alkalosis leading to respiratory failure and coma. Hyperammonemia, elevation of glutamic acid and argininosuccinic acid and its anhydrides confirmed the diagnosis of ALD. He is now 9 years old and severely retarded. Case 2. A male infant with history of lethargy, poor feeding on day 3, treated as sepsis and required respiratory support for 6 days; subsequently readmitted at age 2 weeks with vomitting, lethargy, seizure activity and hyperammonemia, and was treated by a local pediatrician in Songkhla province. There was a history of parental consanguinity and he was referred to Siriraj Hospital on day 64 with severe essential amino acid deficiency and acrodermatitis enteropathica with markedly elevated plasma citrulline level. In spite of aggressive treatment; the patient developed sepsis and he expired on day 78. Ornithine transcarbamylase deficiency (OTC) Case 3. An eleven-month-old male infant, the product of a non-consanguineous marriage, developed neonatal onset of hyperammonemia on day 5 after poor feeding, lethargy, hypothermia, seizure, apnea and coma. He was rescued from neonatal hyperammonemic coma on day 9 after aggressive treatment, but expired at eleven months of age after overwhelming sepsis. Case 4. A male infant, sibling of case 3 was referred to Siriraj Hospital on day 8 with hyperammonemia and coma. In spite of intensive genetic counseling given after the birth of their first child with OTC, the couple chose to have another baby without informing any physician. The baby developed vomiting and lethargy on day 2; subsequently hyperammonemia was noted. In spite of aggressive treatment given; hepatic dysfunction, renal failure and disseminated intravascular coagulation defects occurred on day 15. He expired on day 18 after parental permission for discontinuation of all treatment. Argininosuccinate synthetase deficiency (ASS) or Citrullinemia. Case 5. A seven week old female infant, the product of a consanguineous marriage and of Pakistani ethnic origin; developed intermittent vomiting from day 6. Initial diagnoses included ruminations, sepsis and pyloric stenosis for which she was operated on (day 30); however, vomiting continued; subsequently seizures, hyperammonemic coma developed and she was rescued from hyperammonemic coma within 30 hours. Significant elevations of citrulline and L-glutamine were demonstrated. She was discharged in excellent condition to her home in Dubai, the United Arab Emirates.

Inherited metabolic disorders in Thailand.

The study of inborn errors of metabolism (IEM) in Thailand is in its infancy. The majority are clinically diagnosed since there are only a handful of clinicians and scientists with expertise in inherited metabolic disorders, shortage of well-equipped laboratory facilities and lack of governmental financial support. Genetic metabolic disorders are usually not considered a priority due to prevalence of infectious diseases and congenital infections. From a retrospective study at the Medical Genetics Unit, Department of Pediatrics, Siriraj Hospital; estimated pediatrics patients with suspected IEM were approximately 2-3 per cent of the total pediatric admissions of over 5,000 annually. After more than 10 years of research and accumulated clinical experiences, a genetic metabolic center is being established in collaboration with expert laboratories both in Bangkok (Chulabhorn Research Institute) and abroad (Japan and the United States). Numerous inherited metabolic disorders were identified--carbohydrate, amino acids, organic acids, mitochondrial fatty acid oxidation, peroxisomal, mucopolysaccharidoses etc. This report includes the establishment of genetic metabolic center in Thailand, research and pilot studies in newborn screening in Thailand and a multicenter study from 5 institutions (Children's National Center, King Chulalongkorn Memorial Hospital, Pramongkutklao Hospital, Ramathibodi and Siriraj Hospitals). Inherited metabolic disorders reported are fructose-1,6-bisphosphatase deficiency, phenylketonuria, homocystinuria, nonketotic hyperglycinemia, urea cycle defect (arginino succinate lyase deficiency, argininosuccinate synthetase deficiency), Menkes disease, propionic acidemia and mucopolysaccharidoses (Hurler, Hurler-Scheie).

Mitochondrial fatty acid oxidation disorders in Thai infants: a report of 3 cases.

Three infants with documented mitochondrial fatty acid oxidation disorders are described in this report. Case 1. Carnitine/acylcarnitine translocase deficiency. (CACT) (OMIM 212138) A two-day-old male developed sudden cardiac arrest 48 hours postpartum, with a previous history of early death (day 2) in siblings with a history of parental consanguinity; somnolence, inactivity, refusal to suck within 24 h, hepatomegaly, persistent hypoglycemia, hypocalcemia, hyperkalemia and severe metabolic acidosis prior to cardiac arrest. Dried blood spots by tandem mass spectrometry demonstrated 10 x elevation of palmitoylcarnitine, moderate elevation of oleylcarnitine, steroylcarnitine and myristoylcarnitine. Case 2. Medium chain acyl CoA dehydrogenase (MCAD) deficiency. (OMIM 212139) A six-week-old male infant, developed sudden cardiac arrest after contacting a viral illness, resuscitated successfully in the first episode, only to succumb during the second episode, 2 weeks apart. Plasma acylcarnitine via tandem mass spectrometry was reported normal; however, urine organic acids via gas liquid chromatography and mass spectrometry demonstrated characteristic metabolites consistent with MCADD. Case 3. Carnitine deficiency, systemic primary. (CDSP) (OMIM 212140) A one-year-old girl with progressive dyspnea since birth and a history of parental consanguinity. Severe dilated cardiomyopathy with episodes of cardiac decompensations, hepatomegaly, anemia, generalized hypotonia, but no hypoglycemia were demonstrated prior to cardiac arrest. Extremely low carnitine level noted in dried blood spots via tandem mass spectrometry.

Multiple pterygium syndrome (escobar syndrome).

Escobar (multiple pterygium) syndrome is a rare autosomal recessive disorder characterized by short stature, multiple pterygium, joint contractures, vertebral fusions and minor facial anomalies. There is extreme phenotypic variability. The etiologic and genetic basis of multiple congenital pterygium is very heterogenous. Mutidisciplinary approach includes primary care physician or pediatrician, orthopedist, physical therapist and plastic surgeon. We report a case of multiple pterygium syndrome most likely the first reported case in Thailand that still alive and have had successful operative treatment of the spine and left foot. This 5-year-old Thai girl with short stature, ptosis of both eyelids, antimongoloid slant of palpebral fissures, hypertelorism, micrognathia, flat facies with emotionless expression, pterygium at neck, axillae, antecubital, popliteal, thumbs in palms, talipes equinovarus deformity, scoliolordosis at thoracic spine was described. She went through successive operations : plastic surgical correction of ptosis of both eyelids; anterior spinal fusion at thoracic spine; postero medical release at left foot with good result.

Fragile X syndrome: Case report and review of literature.

Fragile X syndrome or X-linked mental retardation (XLMP) is one of the most common and perplexing discoveries in modern medical genetics. The association of the fragile X chromosome with mental retardation was originally described by Lubs (1969) in his report of a large kindred with XLNR. The incidence is 1 in 2000 males. It is characterized by moderately severe mental retardation in males and inducible cytogenetic marker (a fragile site) on the long arm of the X chromosome (Xq 27.3). Growth in folate-deficient media or addition of folic acid antagonist methotrexate (MTX), induces expression of fragile X. Phenotypic features include long and narrow face, prominent forehead and jaws, large protruding ears and macroorchidism. Disabilities range from varying degree of learning problems to mental retardation, severe language delay, behaviour problems, autism or autistic-like behaviour, hyperactivity, delayed motor bevelopment and poor sensory skills. Joint hypermobility, hypotonia and mitral valve prolapse are also common features. We reported an eight-year-old male who was referred for evaluation of speech problem and mental retardation. The cytogenetic study demonstrated 46, XY, fra (X) q 27.3. Exhaustive review of literature is also summarized. This is most likely first reported case of fragile X syndrome in Thailand.

The study of birth defects in the newborns at Siriraj Hospital (1990-1991).

The study of congenital malformation or birth defects in newborn infants at Siriraj Hospital from September 1990 – September 1991 found 161 newborns with congenital malformation out of 18,958 infants delivered which is 0.9 percent. These were 1.2:1 ratio of males to females. Ninety-five percent were considered malformation. Deformation, disruption and dysplasia were found to be 1.6 percent in each category. The most common malformation were musculoskeletal, central nervous system and gastrointestinal system respectively. This finding was similar to study from Children’s Hospital in 1989. Other congenital malformation was categorized differently. The etiologies of congenital malformation were as follow : 37.4 percent of unknown etiology, 36 percent were multifactorial, 12.4 percent were chromosomal, 6.1 percent were single gene disorders, 6.1 percent were teratogenesis and 2 percent were intrauterine environmental factors.

Primary hyperoxaluria: Cases report.

Primary hyperoxaluria is a rare disease characterized by recurrent calcium oxalate nephrolithiasis and nephrocalcinosis. The most diagnostic laboratory finding if an increased amount of urinary oxalate. The inheritance is presumed to be autosomal recessive but autosomal dominant has been repoeted. Here are reported cases of a family: a boy, his brother, and his father. The boy, the most severely affected died at the age of 8 years. His 6-year-old brother, treated by 6 episodes of Extracorporeal Piezo Electric Lithotripsy (EPL); followed with high doses of pyridoxine and thiazides orally, is still alive with normal renal function. His father was treated by 6 episodes of EPI but without medication. The authors suggest that investigations for metabolic causes should be done in children with positive family history of nephrolithiasis.