Clinical and molecular analysis of two Chinese siblings with Bloom syndrome / 中华儿科杂志

Objective@#To expand the knowledge of the clinical and molecular characteristics of the children with Bloom syndrome.@*Methods@#Clinical data of two siblings with classic Bloom syndrome of Shanghai Children's Medical Center from January 2009 to June 2017 were obtained and analyzed. The DNA of peripheral blood was collected from two Bloom syndrome siblings and their parents during 2015. The mutations were detected with high-throughput sequencing by Illumina sequencing platform.@*Results@#The two siblings (probands) visited our department for short stature and growth retardation, they had full-term normal delivery after normal pregnancy of their mother. Both cases presented with feeding difficulties, malnutrition, microcephaly and mental retardation, repeated infection, symmetrical short stature and special faces. At first, the proband was an 8-year-3-month old girl, her height was 99.7 cm, body mass index (BMI) 12.07 kg/m2, head circumference was 45.5 cm, and birth weight was 1.6 kg. Her younger brother was 3-year-11-month old, his height was 86.6 cm, BMI was 14 kg/m2, birth weight was 1.95 kg, and the head circumference reached 36 cm at 16 months. No evidence of cancer and characteristic rash was detected at 8-year follow-up. Pathogenic complex heterozygous mutations c.772_773delCT, p.Leu258Glufs*7 and c.959+ 2T>A in BLM gene were detected in both siblings, which were separately inherited from their unaffected parents. Besides , c.959 + 2T>A has not been reported previously.@*Conclusions@#Children with Bloom syndrome are characterized by short stature, microcephaly, special faces, feeding difficulties, and immunodeficiency. And butterfly erythematous rash may be absent. The c.959+2T>A mutation detected in our patients maybe a novel pathogenic mutation.

Clinical and molecular analysis of two Chinese siblings with Cockayne syndrome / 中华儿科杂志

<p><b>OBJECTIVE</b>Cockayne syndrome is a rare disease and difficult to be recognized. This study aimed to expand the knowledge of the clinical and molecular characteristics of the children with Cockayne syndrome (CS).</p><p><b>METHOD</b>Clinical data of two siblings with classic CS of Guangzhou Women and Children's Medical Center from July 2013 to November 2014 were obtained and analyzed. The whole DNA of peripheral blood was collected from two CS siblings and their parents. Amplification of all exons and adjacent introns for ERCC6 gene was conducted using PCR, and measurement of reaction product was performed to find mutation sites by two-way sequencing.</p><p><b>RESULT</b>Two affected siblings were males, and came from unconsanguineous parents, 7 years and 5 months old and 4 years and 8 months old, respectively. They were in treatment because of developmental and mental retardation for years. When they were younger than one year of age, their heights and weight were within normal limits. However, poor growth of height and weight and psychomotor retardation appeared after one and a half years of age, as well as skin and eye sensitivity to sunshine, hearing impairment, optic nerve atrophy, microcephaly, and deep-set eyes. The proband's height was 90.8 cm, and weight 9.1 kg, head circumference 41 cm, and chest circumference 44 cm when he was taken to hospital. The elder brother of the proband had a height of 92 cm, weight 11.2 kg, head circumference 41 cm, and chest circumference 44 cm when he was taken to hospital. When the proband was four and a half years old, ventricular enlargement, hypomyelination, and brain atrophy were detected for his elder brother at 7 years of age by cranial MRI. MRS imaging indicated that damages occurred at the left and right sides of dorsal thalamus, lobus insularis, along with the left half circle of central neurons. Symmetrical calcification on bilateral basal ganglia was found on the brain CT scan. Pathogenic compound heterozygous c. 1357C > T (p.Arg453Ter) and c. 1607T > G (p.Leu536Trp) mutations of ERCC6 gene were identified in the two siblings which were separately inherited from their unaffected parents.</p><p><b>CONCLUSION</b>CS children are usually normal at birth, however, they have severe clinical characteristics such as poor growth, psychomotor retardation, cerebral injury, microcephalus, deep-set eyes, and skin sensitivity to sunshine. ERCC6 gene mutation usually occurs, and it is easy to misdiagnose CS as cerebral palsy, primary microcephaly, and so on.</p>

Kniest dysplasia due to mutation of COL2A1 gene / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect potential mutation of COL2A1 gene in two children suspected for Kniest dysplasia.</p><p><b>METHODS</b>The 54 exons and splicing regions of the COL2A1 gene were amplified with PCR and the product was subjected to direct sequencing.</p><p><b>RESULTS</b>A missense mutation (c.905C>T, p.Ala302Val) was found in the coding region of the COL2A1 gene, which has been previously reported in abroad. The patients appeared to have short trunk dwarfism, enlarged joints and midface hypoplasia.</p><p><b>CONCLUSION</b>The probands are the first cases of Kniest dysplasia described in China, and so was the p.Ala302Val mutation.</p>

Clinical features of pyruvate dehydrogenase complex deficiency and gene testing in one case / 中华儿科杂志

<p><b>OBJECTIVE</b>To analyze the clinical characteristics and genetype of one children who had been diagnosed with pyruvate dehydrogenase complex deficiency.</p><p><b>METHOD</b>Comprehensive analyses of this case were performed, including clinical symptoms, signs, biochemical examinations and therapeutic effects. The eleven exons and splicing areas of PDHA1 were amplified with genomic DNA from whole blood. And variations were investigated by sequencing the PCR product. The patient was diagnosed with pyruvate dehydrogenase complex deficiency by sequence analysis of PDHA1 gene.</p><p><b>RESULT</b>The patient was a 2 years and 4 monthes old boy. He presented with muscle hypotonia and weakness for one year, and experienced recurrent episodes of unstable head control, unable to sit by himself or stand without support, with persistently hyperlactacidemia. Metabolic testing revealed blood lactate 5.37 mmol/L, pyruvate 0.44 mmol/L, and lactate/pyruvate ratio was 12.23. MRI of the brain showed hyperintense signals on the T2 and T2 Flair weighted images in the basal ganglia bilaterally. Sequence analysis of PDHA1 gene showed a G>A point mutation at nucleotide 778, resulting in a substitution of glutarnine for arginine at position 263 (R263Q). And the diagnosis of pyruvate dehydrogenase complex deficiency was identified. By giving the therapy with ketogenic diet, vitamin B(1), coenzyme Q(10) and L-carnitine , the boy was in a stable condition.</p><p><b>CONCLUSION</b>The severity and the clinical phenotypes of pyruvate dehydrogenase complex deficiency varied. Sequence analysis of PDHA1 gene revealed a 788G>A (R263Q) mutation. Patients who presented with unexplained muscle hypotonia, weakness and hyperlactacidemia could be diveded by gene analysis. And appropriate treatment can improve the quality of life.</p>

Current status of pyruvate dehydrogenase complex deficiency / 国际儿科学杂志

Pyruvate dehydrogenase complex (PDHc)deficiency is a genetic disorder of mitochondrial energy metabolism.Most cases result from mutations in gene encoded PDHc.The clinical presentation of patients with PDHc deficiency is extremely variable.Diagnosis of PDHc deficiency remains challenging,which depends on definitive enzymatic assays and DNA analysis.We review the relevant literature of recent domestic and international research results,in order to enhance our awareness of this disease and reduce misdiagnosis and missed diagnosis.It is helpful to improve prognosis and quality of life of patients by earlier and essential treatment.