Central nervous system manifestations of LRBA deficiency: case report of two siblings and literature review.

BACKGROUND: LPS-responsive beige-like anchor protein (LRBA) deficiency is a primary immunodeficiency disease (PID) characterized by a regulatory T cell defect resulting in immune dysregulation and autoimmunity. We present two siblings born to consanguineous parents of North African descent with LRBA deficiency and central nervous system (CNS) manifestations. As no concise overview of these manifestations is available in literature, we compared our patient's presentation with a reviewed synthesis of the available literature. CASE PRESENTATIONS: The younger brother presented with enteropathy at age 1.5 years, and subsequently developed Evans syndrome and diabetes mellitus. These autoimmune manifestations led to the genetic diagnosis of LRBA deficiency through whole exome sequencing with PID gene panel. At 11 years old, he had two tonic-clonic seizures. Brain MRI showed multiple FLAIR-hyperintense lesions and a T2-hyperintense lesion of the cervical medulla.  His sister presented with immune cytopenia at age 9 years, and developed diffuse lymphadenopathy and interstitial lung disease. Genetic testing confirmed the same mutation as her brother. At age 13 years, a brain MRI showed multiple T2-FLAIR-hyperintense lesions. She received an allogeneic hematopoietic stem cell transplantation (allo-HSCT) 3 months later. Follow-up MRI showed regression of these lesions. CONCLUSIONS: Neurological disease is documented in up to 25% of patients with LRBA deficiency. Manifestations range from cerebral granulomas to acute disseminating encephalomyelitis, but detailed descriptions of neurological and imaging phenotypes are lacking. LRBA deficiency amongst other PIDs should be part of the differential diagnosis in patients with inflammatory brain lesions. We strongly advocate for a more detailed description of CNS manifestations in patients with LRBA deficiency, when possible with MR imaging. This will aid clinical decision concerning both anti-infectious and anti-inflammatory therapy and in considering the indication for allo-HSCT.

Expanding the clinical spectrum of biallelic ZNF335 variants.

ZNF335 plays an essential role in neurogenesis and biallelic variants in ZNF335 have been identified as the cause of severe primary autosomal recessive microcephaly in 2 unrelated families. We describe, herein, 2 additional affected individuals with biallelic ZNF335 variants, 1 individual with a homozygous c.1399 T > C, p.(Cys467Arg) variant, and a second individual with compound heterozygous c.2171_2173delTCT, p.(Phe724del) and c.3998A > G, p.(Glu1333Gly) variants with the latter variant predicted to affect splicing. Whereas the first case presented with early death and a severe phenotype characterized by anterior agyria with prominent extra-axial spaces, absent basal ganglia, and hypoplasia of the brainstem and cerebellum, the second case had a milder clinical presentation with hypomyelination and otherwise preserved brain structures on MRI. Our findings expand the clinical spectrum of ZNF335-associated microcephaly.

Polymicrogyria with dysmorphic basal ganglia? Think tubulin!

Dominant mutations in TUBB2B have been reported in patients with polymicrogyria. We further explore the phenotype associated with mutations in TUBB2B. Twenty patients with polymicrogyria (five unilateral) were tested for mutations in TUBB2B by Sanger sequencing. We identified two novel de novo mutations, c.743C>T (p.Ala248Val) and c.1139G>T (p.Arg380Leu) in exon 4 of TUBB2B in three unrelated families. Brain magnetic resonance images showed polymicrogyria involving predominantly the perisylvian regions. In addition, there was a dysmorphic appearance of the basal ganglia, thin corpus callosum, enlargement of the ventricles, thinning of the white matter and hypoplasia of pons and cerebellar vermis. This combination of associated features was absent in all 17 patients with polymicrogyria in whom no mutation was identified. This report underlines that the association of polymicrogyria with thin or absent corpus callosum, dysmorphic basal ganglia, brainstem and vermis hypoplasia is highly likely to result from mutations in TUBB2B and provides further insight in how mutations in TUBB2B affect protein function.

Clinical and genetic aspects of PCDH19-related epilepsy syndromes and the possible role of PCDH19 mutations in males with autism spectrum disorders.

Epilepsy and mental retardation limited to females (EFMR), caused by PCDH19 mutations, has a variable clinical expression that needs further exploration. Onset of epilepsy may be provoked by fever and can resemble Dravet syndrome. Furthermore, transmitting males have no seizures, but are reported to have rigid personalities suggesting possible autism spectrum disorders (ASD). Therefore, this study aimed to determine the phenotypic spectrum associated with PCDH19 mutations in Dravet-like and EFMR female patients and in males with ASD. We screened 120 females suffering from Dravet-like epilepsy, 136 females with EFMR features and 20 males with ASD. Phenotypes and genotypes of the PCDH19 mutation carriers were compared with those of 125 females with EFMR reported in the literature. We report 15 additional patients with a PCDH19 mutation. Review of clinical data of all reported patients showed that the clinical picture of EFMR is heterogeneous, but epilepsy onset in infancy, fever sensitivity and occurrence of seizures in clusters are key features. Seizures remit in the majority of patients during teenage years. Intellectual disability and behavioural disturbances are common. Fifty percent of all mutations are missense mutations, located in the extracellular domains only. Truncating mutations have been identified in all protein domains. One ASD proband carried one missense mutation predicted to have a deleterious effect, suggesting that ASD in males can be associated with PCDH19 mutations.

TUBA1A mutations: from isolated lissencephaly to familial polymicrogyria.

BACKGROUND: Mutations in the TUBA1A gene have been reported in patients with lissencephaly and perisylvian pachygyria. METHODS: Twenty-five patients with malformations of cortical development ranging from lissencephaly to polymicrogyria were screened for mutations in TUBA1A. RESULTS: Two novel heterozygous missense mutations in TUBA1A were identified: c.629A>G (p.Tyr210Cys) occurring de novo in a boy with lissencephaly, and c.13A>C (p.Ile5Leu) affecting 2 sisters with polymicrogyria whose mother presented somatic mosaicism for the mutation. CONCLUSIONS: Mutations in TUBA1A have been described in patients with lissencephaly and pachygyria. We report a mutation in TUBA1A as a cause of polymicrogyria. So far, all mutations in TUBA1A have occurred de novo, resulting in isolated cases. This article describes familial recurrence of TUBA1A mutations due to somatic mosaicism in a parent. These findings broaden the phenotypic spectrum associated with TUBA1A mutations and have implications for genetic counseling.

HPV types causing juvenile recurrent laryngeal papillomatosis in South Africa.

OBJECTIVES: To identify human papillomavirus (HPV) types associated with juvenile onset recurrent laryngeal papillomatosis (RLP) in southern Africa, to determine if there is a correlation between HPV type and disease aggressiveness and to determine the diagnostic and prognostic value of rapid molecular techniques for detection and typing of HPV using laryngeal biopsies. METHODS: Laryngeal biopsies from patients undergoing surgery for RLP were screened for HPV using conventional and real-time PCR techniques. Amplicons were sequenced to determine the HPV type involved. Clinical features were correlated with HPV type. RESULTS: HPV was identified in papillomata from 18 out of 19 patients. Only HPV-6 and HPV-11 were identified, with no co-infections. There was 100% concordance between conventional and real-time PCR techniques. Patients with HPV-11 disease required more procedures and tended to have higher Derkay scores than those with HPV-6 disease. The HPV types identified in our patients were genetically similar to HPV types from geographically distinct regions. CONCLUSIONS: RLP in our patient population appears to be exclusively due to HPV-6 or HPV-11. HPV-11 disease appears to be more aggressive than HPV-6 disease. Identification of the HPV types provides motivation for inclusion of vaccines against these types in vaccination programs to protect women against infection and subsequently reduce the incidence of RLP.

Transport in QSAR VIII. The influence of viscosity on transport rate constants in two-phase systems organic solvent-water.

In the system cyclohexane-water transport rate constants and partition coefficients of nine sulfonamides are determined at six temperatures. Kinematic viscosities of the organic and aqueous layer are determined at the same temperatures. Experimentally bilinear relationships between transport rate constants and partition coefficients are obtained in good agreement with theory. According to this theory convection and diffusion are important features in the overall transport process. Using the experimental data, the influence of viscosity on transport rate constants is established and expressed in terms of the relationships between maximum transport rate constants and viscosities. These relationships correspond with laminar flow at both sides of the interface.

The contribution of classical risk factors to cardiovascular disease in familial hypercholesterolaemia: data in 2400 patients.

OBJECTIVE: To determine the contribution of classical risk factors to the development of cardiovascular disease (CVD) in patients with heterozygous familial hypercholesterolaemia (FH). DESIGN: A retrospective, multi-centre, cohort study. Extensive data were collected by scrutinizing medical records and the use of questionnaires. Multivariate Cox regression was used to study the relationship between potential risk factors and the occurrence of CVD. SETTING AND SUBJECTS: We included 2400 FH patients from 27 Dutch lipid clinics. The diagnosis of FH was based upon the presence of a low-density lipoprotein receptor mutation or upon strict clinical criteria. MAIN OUTCOME MEASURES: Cardiovascular mortality and CVD. RESULTS: During 112.943 person-years, 782 (32.6%) patients had had at least one cardiovascular event. Male gender (RR 2.82, 95% CI 2.37-3.36), smoking (RR 1.67, 95% CI 1.40-1.99), hypertension (RR 1.36, 95% CI 1.06-1.75), diabetes mellitus (RR 2.19, 95% CI 1.36-3.54), low HDL-C (RR 1.37, 95% CI 1.15-1.63) and elevated lipoprotein(a) levels (RR 1.50, 95% CI 1.20-1.79) proved to be independent CVD risk factors. These six risk factors explained 18.7% of the variation in the occurrence of CVD. CONCLUSIONS: Male gender, smoking, hypertension, diabetes mellitus, HDL cholesterol and lipoprotein(a) levels proved to be important risk factors for CVD in FH patients. In addition to the routine institution of statin therapy, controlling these factors needs special attention in the management of this disorder.