MACF1 Mutations Encoding Highly Conserved Zinc-Binding Residues of the GAR Domain Cause Defects in Neuronal Migration and Axon Guidance.

To date, mutations in 15 actin- or microtubule-associated genes have been associated with the cortical malformation lissencephaly and variable brainstem hypoplasia. During a multicenter review, we recognized a rare lissencephaly variant with a complex brainstem malformation in three unrelated children. We searched our large brain-malformation databases and found another five children with this malformation (as well as one with a less severe variant), analyzed available whole-exome or -genome sequencing data, and tested ciliogenesis in two affected individuals.

Neuropsychiatric comorbidities in adults with phenylketonuria: A retrospective cohort study.

Adults with phenylketonuria (PKU) may experience neurologic and psychiatric disorders, including intellectual disability, anxiety, depression, and neurocognitive dysfunction. Identifying the prevalence and prevalence ratios of these conditions will inform clinical treatment. This nested, case-controlled study used International Classification of Diseases, Ninth Revision (ICD-9) codes from the MarketScan® insurance claims databases from 2006 to 2012 and healthcare claims data for US-based employer and government-sponsored health plans.

Durable and sustained immune tolerance to ERT in Pompe disease with entrenched immune responses.

Background: Enzyme replacement therapy (ERT) has prolonged survival and improved clinical outcomes in patients with infantile Pompe disease (IPD), a rapidly progressive neuromuscular disorder. Yet marked interindividual variability in response to ERT, primarily attributable to the development of antibodies to ERT, remains an ongoing challenge. Immune tolerance to ongoing ERT has yet to be described in the setting of an entrenched immune response.

Multi-system involvement in a severe variant of fibrodysplasia ossificans progressiva (ACVR1 c.772G>A; R258G): A report of two patients.

Severe variants of fibrodysplasia ossificans progressiva (FOP) affect <2% of all FOP patients worldwide, but provide an unprecedented opportunity to probe the phenotype-genotype relationships that propel the pathology of this disabling disease. We evaluated two unrelated children who had severe reduction deficits of the hands and feet with absence of nails, progressive heterotopic ossification, hypoplasia of the brain stem, motor and cognitive developmental delays, facial dysmorphology, small malformed teeth, and abnormal hair development. One child had sensorineural hearing loss, microcytic anemia, and a tethered spinal cord and the other had a patent ductus arteriosus and gonadal dysgenesis with sex reversal (karyotype 46, XY female).

Bortezomib in the rapid reduction of high sustained antibody titers in disorders treated with therapeutic protein: lessons learned from Pompe disease.

Purpose: High sustained antibody titers complicate many disorders treated with a therapeutic protein, including those treated with enzyme replacement therapy, such as Pompe disease. Although enzyme replacement therapy with alglucosidase alfa (Myozyme) in Pompe disease has improved the prognosis of this otherwise lethal disorder, patients who develop high sustained antibody titers to alglucosidase alfa enter a prolonged phase of clinical decline resulting in death despite continued enzyme replacement therapy. Clinically effective immune-tolerance induction strategies have yet to be described in the setting of an entrenched immune response characterized by high sustained antibody titers, wherein antibody-producing plasma cells play an especially prominent role.

The impact of antibodies on clinical outcomes in diseases treated with therapeutic protein: lessons learned from infantile Pompe disease.

Purpose: Enzyme replacement therapy with rhGAA (Myozyme®) has lead to improved survival, which is largely attributable to improvements in cardiomyopathy and skeletal muscle function. However, crossreactive immunologic material-negative patients have a poor clinical response to enzyme replacement therapy secondary to high sustained antibody titers. Furthermore, although the majority of crossreactive immunologic material-positive patients tolerize or experience a downtrend in anti-rhGAA antibody titers, antibody response is variable with some crossreactive immunologic material-positive infants also mounting high sustained antibody titers.

Maternal systemic primary carnitine deficiency uncovered by newborn screening: clinical, biochemical, and molecular aspects.

Background: Systemic primary carnitine deficiency is an autosomal recessive disorder of the carnitine cycle caused by mutations in the SLC22A5 gene that encodes the carnitine transporter, organic cation transporter. Systemic primary carnitine deficiency typically presents in childhood with either metabolic decompensation or cardiomyopathy. We report five families in which low free carnitine levels in the infants' newborn screening have led to the diagnosis of maternal systemic primary carnitine deficiency.

Progressive and symmetric supraorbital hyperostosis with bony and soft tissue overgrowth in an Ethiopian female: a newly recognized overgrowth syndrome?

We report on an Ethiopian female with generalized overgrowth of postnatal onset accompanied by progressive and symmetric overgrowth of skeletal and soft tissues. Her phenotype consisted of progressive and symmetric overgrowth of the supraorbital ridges, glabella, occiput, cervical spine, and distal phalanges of all extremities, but particularly the 3rd and 4th digits. She also has overgrowth of soft tissues of the posterior neck (thought to be fatty in origin), alveolar hyperplasia, and overgrowth of the skin comprising the areola and umbilicus.

Early neonatal diagnosis of long-chain 3-hydroxyacyl coenzyme a dehydrogenase and mitochondrial trifunctional protein deficiencies.

Tandem mass spectrometry (MS/MS) has been introduced in several newborn screening programs for the detection of a large number of inborn errors of metabolism, including fatty acid oxidation disorders (FAOD). Early identification and treatment of FAOD have the potential to improve outcome and may be life-saving in some cases; an estimated 5% of sudden infant deaths are attributable to undiagnosed disorders of fatty acid oxidation. We report very early neonatal presentations of long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) and mitochondrial trifunctional protein (TFP) deficiencies confirmed by molecular analysis.

Identification of a peptide directed against the anti-CD34 antibody, 9C5, by phage display and its use in hematopoietic stem cell selection.

A peptide sequence was identified by phage display technology that could be used as an alternative to chymopapain for the release of hematopoietic progenitor cells captured by anti-CD34 monoclonal antibodies. This was achieved by affinity selection screening (biopanning) of a random hexapeptide sequence phage display library. Four rounds of biopanning were performed to enrich for phage clones with specific affinity for anti-CD34 monoclonal antibody, 9C5.

Prader-Willi syndrome is caused by disruption of the SNRPN gene.

A Prader-Willi syndrome patient is described who has a de novo balanced translocation, (4;15)(q27;q11.2)pat, with breakpoints lying between SNRPN exons 2 and 3. Parental-origin studies indicate that there is no uniparental disomy and no apparent deletion.

Molecular analysis of skewed Tcra-V gene use in T-cell receptor beta-chain transgenic mice.

The influence of beta-chain diversity on the expressed T-cell receptor (TCR) alpha-chain repertoire was investigated using transgenic mice which exclusively express a single rearranged TCR beta-chain gene. Analysis of these mice using alpha-chain-specific recombinant cDNA libraries showed that expression of the transgene-encoded beta chain results in significant skewing in Tcra-V gene segment usage vs nontransgenic mice. Skewing was most pronounced towards alpha chains using TCRA-V segments.

The clinical phenotype of succinic semialdehyde dehydrogenase deficiency (4-hydroxybutyric aciduria): case reports of 23 new patients.

Objectives: To further define the clinical spectrum of the disease for pediatric and metabolic specialists, and to suggest that the general pediatrician and pediatric neurologist consider succinic semialdehyde dehydrogenase (SSADH) deficiency in the differential diagnosis of patients with (idiopathic) mental retardation and emphasize the need for accurate, quantitative organic acid analysis in such patients.

Patients: The clinical features of 23 patients (20 families) with SSADH deficiency (4-hydroxybutyric acid-uria) are presented. The age at diagnosis ranged from 3 months to 25 years in the 11 male and 12 female patients; consanguinity was noted in 39% of families.

Simpson-Golabi-Behmel syndrome: genotype/phenotype analysis of 18 affected males from 7 unrelated families.

Simpson-Golabi-Behmel syndrome (SGBS) is an X-linked overgrowth disorder recently shown to be caused by mutations in the heparan sulfate proteoglycan GPC3 [Pilia et al., Nat Genet; 12:241-247 1996]. We have used Southern blot analysis and polymerase chain reaction amplification of intra-exonic sequences to identify four new GPC3 mutations and further characterize three previously reported SGBS mutations.

Mitochondrial short-chain L-3-hydroxyacyl-coenzyme A dehydrogenase deficiency: a new defect of fatty acid oxidation.

We describe two children with deficiency of short-chain L-3-hydroxyacyl-CoA dehydrogenase, a new disorder of the mitochondrial beta-oxidation of straight-chain fatty acids. The patients presented with fasting-induced vomiting, and ketosis and low blood glucose, features typical of ketotic hypoglycemia were documented in one. Enzyme assays were performed in cultured skin fibroblasts.

Facial features of infants exposed prenatally to cocaine.

Thirty two infants referred for in-patient genetics evaluation at the University of California at San Francisco, 1987-1992, were found to have a history of maternal cocaine use. Genetics reports and medical records were reviewed on all these infants to identify features distinctive for cocaine exposure. Among these 32 cases, 14 infants were exposed only to cocaine; 18 were exposed to alcohol and cocaine.

The ht beta gene encodes a novel CACCC box-binding protein that regulates T-cell receptor gene expression.

A gene encoding a novel CACCC box-binding protein that binds to the promoter region of the human T-cell receptor (TCR) V beta 8.1 gene and the mouse TCR alpha gene silencer has been cloned. This gene, termed ht beta, contains four zinc fingers of the class Cys2-X12-His2 that may be responsible for DNA binding and a highly negatively charged region that defines a putative transcriptional activation domain.

Structure-function relationship among T-cell receptors specific for lysozyme peptides bound to Ab or Abm-12 molecules.

The alpha beta T-cell receptor (TCR) recognizes antigenic peptides bound to major histocompatibility complex (MHC) molecules. In contrast to the antibody combining site, for which the antigen contact or complementarity-determining residues (CDRs) have been precisely defined, the location and function of the corresponding CDR regions of the alpha and beta TCR chains are not known. To develop a model system for systematic analysis of the CDRs of the alpha beta TCR, we isolated a panel of murine T-cell clones that recognize a lysozyme peptide containing residues 74-88 bound to either Ab or Abm-12 MHC class II molecules.

Abnormalities of the visual system in infants exposed to cocaine.

The authors describe 13 cocaine-exposed infants with optic nerve abnormalities, delayed visual maturation, and prolonged eyelid edema. Prolonged and potentially vision-threatening eyelid edema is a new clinical entity. The pharmacology of cocaine, its easy access to fetal circulation, and its neurotropic characteristics can be used to explain optic nerve abnormalities and delayed visual maturation.

Segregation of the Huntington disease region of human chromosome 4 in a somatic cell hybrid.

We have developed an X-irradiation:cell fusion procedure that segregates segments of human chromosomes lacking selectable markers and have used this approach to construct somatic cell hybrids retaining fragments of human chromosome 4 as the only human material. To identify hybrids retaining a small chromosomal fragment in the region of the Huntington disease (HD) gene, we used Southern blot analysis to screen 72 hybrid lines for the presence or absence of seven chromosome 4 single-copy loci. These data, combined with in situ hybridization experiments, identified three hybrids of interest.

Structure of Escherichia coli dnaC. Identification of a cysteine residue possibly involved in association with dnaB protein.

The nucleotide sequence of the Escherichia coli dnaC gene and the primary structure of the dnaC protein were determined. The NH2-terminal amino acid sequence of the dnaC protein matched that predicted from the nucleotide sequence of the 735-base pair coding region. The dnaC gene lacks characteristic promoter structures; neither the "Pribnow box" nor the "-35 sequence" was detected within 222 base pairs upstream from the initiator ATG codon.

Molecular characterization of meiotic recombination within the major histocompatibility complex of the mouse: mapping of crossover sites within the I region.

The molecular analysis of crossing-over within the mouse major histocompatibility complex provides a useful approach for the study of the structural characteristics of meiotic recombination. In this study five intra-I-region recombinants, each derived from Ik/Ib heterozygotes, were characterized for restriction-fragment length polymorphisms (RFLPs) characteristic of the I region of the two parental strains. Southern blot analysis of intra-I recombinant strains A.

Arhinencephaly. The spectrum of associated malformations.

Eight cases are presented of arhinencephaly and its associated malformations, which included 2 examples of holoprosencephaly and 3 of agenesis of the corpus callosum. Additional features included cortical malformations, anomalies of the long tracts and of the optic pathway, cerebellar hypoplasia and dentato-olivary dysplasia. Each of these components covered a wide spectrum ranging in severity from extreme to minimal.

Molecular analysis of the hotspot of recombination in the murine major histocompatibility complex.

Biological and serological assays have been used to define four subregions for the I region of the major histocompatibility complex (MHC) in the order I-A, I-B, I-J, and I-E. The I-J subregion presumably encodes the I-J polypeptide of the elusive T-cell suppressor factors. Restriction enzyme site polymorphisms and DNA sequence analyses of the I region from four recombinant mouse strains were used to localize the putative I-B and I-J subregions to a 1.

Specific-primer-directed DNA sequencing.

A simple and rapid strategy for DNA sequence analysis based on the Sanger chain-termination method is described. This procedure utilizes full-sized inserts of 1 to 4 kb of DNA cloned into M13 bacteriophage vectors. After the sequence of the first 600-650 bp of the insert DNA has been determined with the commercially available universal vector primer, a specific oligonucleotide is synthesized utilizing the sequence data obtained from the 3' end of the sequence and used as a primer to extend the sequence analysis for another 600-650 nucleotides.