Ryanodine receptor 1 related myasthenia like myopathy responsive to pyridostigmine.

Disease causing variants in the Ryanodine receptor 1 (RYR1) gene are a common cause for congenital myopathy and for malignant hyperthermia susceptibility. We report a 17 year old boy with congenital muscle weakness progressing to a myasthenia like myopathy with muscle weakness, fatigability, ptosis, and ophthalmoplegia. Muscle biopsy showed predominance and atrophy of type 1 fibers. Whole-exome trio sequencing revealed three variants in the RYR1-gene in the patient: c.6721C > T,p.(Arg2241*) and c.2122G > A,p.(Asp708Asn) in cis position, and the c.325C > T,p.(Arg109Trp) variant in trans. Treatment with pyridostigmine improved symptoms. This case supports that a myasthenia like phenotype is part of the phenotypic spectrum of RYR1 related disorders, and that treatment with pyridostigmine can be beneficial for patients with this phenotype.

Nablus mask-like facial syndrome: deletion of chromosome 8q22.1 is necessary but not sufficient to cause the phenotype.

Nablus mask-like facial syndrome (NMLFS) has many distinctive phenotypic features, particularly tight glistening skin with reduced facial expression, blepharophimosis, telecanthus, bulky nasal tip, abnormal external ear architecture, upswept frontal hairline, and sparse eyebrows. Over the last few years, several individuals with NMLFS have been reported to have a microdeletion of 8q21.3q22.1, demonstrated by microarray analysis. The minimal overlapping region is 93.98-96.22 Mb (hg19). Here we present clinical and microarray data from five singletons and two mother-child pairs who have heterozygous deletions significantly overlapping the region associated with NMLFS. Notably, while one mother and child were said to have mild tightening of facial skin, none of these individuals exhibited reduced facial expression or the classical facial phenotype of NMLFS. These findings indicate that deletion of the 8q21.3q22.1 region is necessary but not sufficient for development of the NMLFS. We discuss possible genetic mechanisms underlying the complex pattern of inheritance for this condition.

Transient congenital hyperinsulinism and hemolytic disease of a newborn despite rhesus D prophylaxis: a case report.

BACKGROUND: In neonates, rhesus D alloimmunization despite anti-D immunoglobulin prophylaxis is rare and often unexplained. Rhesus D alloimmunization can lead to hemolytic disease of the newborn with anemia and unconjugated hyperbilirubinemia. In past reports, transient congenital hyperinsulinism has been described as a rare complication of rhesus D alloimmunization. Our case report illustrates that rhesus D alloimmunization can result in a pseudosyndrome with severe congenital hyperinsulinism, anemia, and conjugated hyperbilirubinemia, despite correctly administered anti-D immunoglobulin prophylaxis. CASE PRESENTATION: We report of a 36-year-old, Caucasian gravida 1, para 1 mother with A RhD negative blood type who received routine antenatal anti-D immunoglobulin prophylaxis. Her full term newborn boy presented with severe congenital hyperinsulinism, anemia, and conjugated hyperbilirubinemia up to 295 µmol/L (ref. < 9), accounting for 64% of the total bilirubin. Syndromic congenital hyperinsulinism was suspected. Examinations showed a positive direct antiglobulin test, initially interpreted as caused by irregular antibodies; diffuse congenital hyperinsulinism by 18F-DOPA positron emission tomography/computed tomography scan; normal genetic analyses for congenital hyperinsulinism; mildly elevated liver enzymes; delayed, but present bile excretion by Tc99m-hepatobiliary iminodiacetic acid scintigraphy; and cholestasis and mild fibrosis by liver biopsy. The maternal anti-D titer was 1:16,000 day 20 postpartum. Y-chromosome material in the mother's blood could not be identified. This could, however, not exclude late intrapartum fetomaternal hemorrhage as the cause of immunization. No causative genetic findings were deetrmined by trio whole exome sequencing. The child went into clinical remission after 5.5 months. CONCLUSION: Our case demonstrates that rhesus D alloimmunization may present as a pseudosyndrome with transient congenital hyperinsulinism, anemia, and inspissated bile syndrome with conjugated hyperbilirubinaemia, despite anti-D immunoglobulin prophylaxis, possibly due to late fetomaternal hemorrhage.

Is MED13L-related intellectual disability a recognizable syndrome?

INTRODUCTION: MED13L-related intellectual disability is characterized by moderate intellectual disability (ID), speech impairment, and dysmorphic facial features. We present 8 patients with MED13L-related intellectual disability and review the literature for phenotypical and genetic aspects of previously described patients. MATERIALS AND METHODS: In the search for genetic aberrations in individuals with ID, two of the patients were identified by chromosomal microarray analysis, and five by exome sequencing. One of the individuals, suspected of MED13L-related intellectual disability, based on clinical features, was identified by Sanger sequencing. RESULTS: All 8 individuals had de novo MED13L aberrations, including two intragenic microdeletions, two frameshift, three nonsense variants, and one missense variant. Phenotypically, they all had intellectual disability, speech and motor delay, and features of the mouth (open mouth appearance, macroglossia, and/or macrostomia). Two individuals were diagnosed with autism, and one had autistic features. One had complex congenital heart defect, and one had persistent foramen ovale. The literature was reviewed with respect to clinical and dysmorphic features, and genetic aberrations. CONCLUSIONS: Even if most clinical features of MED13L-related intellectual disability are rather non-specific, the syndrome may be suspected in some individuals based on the association of developmental delay, speech impairment, bulbous nasal tip, and macroglossia, macrostomia, or open mouth appearance.