ABSTRACT
HIBCH (3-hydroxyisobutyryl-CoA hydrolase) deficiency (MIM #250620) is a rare autosomal recessive inborn error of metabolism, leading to a block in the catabolic pathway of the amino acid valine and presumably to accumulation of toxic valine metabolites in mitochondria. Only three families with HIBCH deficiency and biallelic HIBCH mutations have been described. We report on a further patient, first child of healthy consanguineous parents, with severe developmental delay, seizures, hyperintensities of the basal ganglia on magnetic resonance imaging (MRI), progressive brain atrophy, optic nerve atrophy, repeatedly elevated blood lactate, and respiratory chain complexes I, I + III and cytochrome c oxidase deficiencies with borderline depletion of mitochondrial DNA in muscle tissue. Laboratory findings in blood and skeletal muscle were inconsistent and did not allow a definite diagnosis, but supported the hypothesis of mitochondrial dysfunction. Homozygosity mapping and whole-exome sequencing revealed a homozygous one-base pair insertion in HIBCH. Deficiency of enzyme activity was confirmed in cultured fibroblasts. Although relatively unspecific, the clinical features were similar to those of the previously reported cases. Given the clinical variability and large number of differential diagnoses, the prevalence of HIBCH deficiency is probably underestimated. Next-generation sequencing approaches are an effective tool for identifying the underlying genetic basis in patients suspected of mitochondrial disorders.
Subject(s)
Abnormalities, Multiple/genetics , Abnormalities, Multiple/pathology , Amino Acid Metabolism, Inborn Errors/genetics , Amino Acid Metabolism, Inborn Errors/pathology , Mitochondrial Diseases/pathology , Phenotype , Thiolester Hydrolases/deficiency , Base Sequence , Blotting, Western , Brain/pathology , Exome/genetics , Fibroblasts/metabolism , Humans , Magnetic Resonance Imaging , Mitochondrial Diseases/genetics , Molecular Sequence Data , Muscle, Skeletal/pathology , Pedigree , Sequence Analysis, DNA/methods , Thiolester Hydrolases/geneticsABSTRACT
PURPOSE: This study aims to describe the drug use on a Neonatal Intensive Care Unit (NICU) at a University Children's Hospital in Germany, to investigate the licensing status of the drugs used and to conclude critical areas in neonatal intensive care to support prioritisation of future research. METHODS: An 11-month, prospective cohort study was conducted on the NICU at the University Children's Hospital Erlangen, Germany. All products prescribed during the study period were analysed whether or not the SPC contains information on term and preterm neonates. RESULTS: A total of 183 patients (102 male) with a mean gestational age of 33.6 weeks (minimum = 24, maximum = 42) were included. The mean length of hospitalisation was 19.4 days (minimum = 2, maximum = 167). On average, patients received 11.1 drugs (minimum = 0, maximum = 46). The majority of prescriptions were accounted for by antibiotics (n = 515), which were received by 90% of all patients, followed by CNS drugs (n = 448) and respiratory drugs (n = 306). Of all the different drugs prescribed (n = 102) only 38% had information regarding their use in patients aged less than 1 month in their SPC. Analgesics and cardiovascular drugs were prescribed frequently, but without having information for use in neonates. Seventy percent of all patients and 100% of very preterm infants received at least one of these drugs. CONCLUSIONS: Treatment strategies on a preterm intensive care unit are complex and little information is available for the drugs used. Analgesics and cardiovascular drugs are of major concern. Efforts will have to be made to conduct well-designed and powered studies in this vulnerable population.
Subject(s)
Drug Approval , Intensive Care Units, Neonatal , Off-Label Use , Drug Labeling , Drug Utilization , Female , Germany , Hospitalization , Hospitals, Pediatric , Humans , Infant, Newborn , Infant, Premature , Length of Stay , Male , Prospective StudiesABSTRACT
The translocation t(9;11)(p22;q23) is a recurring chromosomal abnormality in acute myeloid leukemia (AML) fusing two genes designated as MLL and AF9. Within MLL, almost all rearrangements cluster in an 8.3-kb restricted region and fuse 5' portions of MLL to a variety of heterologous genes in various 11q23 translocations. AF9 is one of the most common fusion partners of MLL. It spans more than 100 kb, and two breakpoint cluster regions (BCRs) have been identified in a telomeric region of intron 4 (BCR1) and within introns 7 and 8 (BCR2). We investigated 11 children's bone marrow or peripheral blood samples (3 AML, 5 t-AML, 2 ALL, 1 ALL relapse) and two cell lines (THP-1 and Mono-Mac-6) with cytogenetically diagnosed translocations t(9;11). By use of an optimized multiplex nested long-range PCR assay, a breakpoint-spanning DNA fragment from each sample was amplified and directly sequenced. In four patients and two cell lines, the AF9 breakpoints were located within BCR1 and in two patients within BCR2, respectively. However, in five patients the AF9 breakpoints were found outside the previously described BCRs within the centromeric region of intron 4 and even within intron 3 in one case. All five patients with a secondary AML, who had not received etoposides during treatment of the primary malignant disease, revealed almost identical MLL breakpoints very close to a breakage hot spot inducible by topoisomerase II inhibitors or apoptotic triggers in vitro. Sequence patterns around the breakpoints indicated involvement of a "damage-repair mechanism" in the development of t(9;11) similar to t(4;11) in infants' acute leukemia.
