Novel homozygous LAMB1 in-frame deletion in a pediatric patient with brain anomalies and cerebrovascular event.

Biallelic pathogenic variants in LAMB1 have been associated with autosomal recessive lissencephaly 5 (OMIM 615191), which is characterized by brain malformations (cobblestone lissencephaly, hydrocephalus), developmental delay, and epilepsy. Pathogenic variants in LAMB1 are rare, with only 11 pathogenic variants and 11 patients reported to date. Here, we report on a 6-year-old patient from a consanguineous family with profound developmental delay, microcephaly, and a history of a perinatal cerebrovascular event. Brain magnetic resonance imaging (MRI) showed cerebellar cystic defects, signal intensity abnormalities, and a hypoplastic corpus callosum. Trio-exome analysis revealed a homozygous in-frame deletion of Exons 23 and 24 of LAMB1 affecting 104 amino acids including the epidermal growth factor (EGF)-like units 11 and 12 in Domain III. To our knowledge, this is the first reported in-frame deletion in LAMB1. Our findings broaden the clinical and molecular spectrum of LAMB1-associated syndromes.

Acral lamellar ichthyosis with amino acid substitution in the C-terminus of keratin 2.

BACKGROUND: Most cases of hereditary ichthyoses present with generalized scaling and skin dryness. However, in some cases skin involvement is restricted to particular body regions as in acral lamellar ichthyosis. OBJECTIVES: We report on the genetic basis of acral ichthyosis in two families presenting with a similar phenotype. METHODS: Genetic testing was performed by targeted next generation sequencing and whole-exome sequencing. For identity-by-descent analysis, the parents were genotyped and data analysis was performed with the Chromosome Analysis Suite Software. RT-PCR with RNA extracted from skin samples was used to analyse the effect of variants on splicing. RESULTS: Genetic testing identified a few heterozygous variants, but only the variant in KRT2 c.1912 T > C, p.Phe638Leu segregated with the disease and remained the strongest candidate. Pairwise identity-by-descent analysis revealed no indication of family relationship. Phenylalanine 638 is the second last amino acid upstream of the termination codon in the tail of K2, and substitution to leucine is predicted as probably damaging. Assessment of the variant is difficult, in part due to the lack of crystal structures of this region. CONCLUSIONS: Altogether, we show that a type of autosomal dominant acral ichthyosis is most probably caused by an amino acid substitution in the C-terminus of keratin 2.

New Cav1.2 Channelopathy with High-Functioning Autism, Affective Disorder, Severe Dental Enamel Defects, a Short QT Interval, and a Novel CACNA1C Loss-Of-Function Mutation.

Complex neuropsychiatric-cardiac syndromes can be genetically determined. For the first time, the authors present a syndromal form of short QT syndrome in a 34-year-old German male patient with extracardiac features with predominant psychiatric manifestation, namely a severe form of secondary high-functioning autism spectrum disorder (ASD), along with affective and psychotic exacerbations, and severe dental enamel defects (with rapid wearing off his teeth) due to a heterozygous loss-of-function mutation in the CACNA1C gene (NM_000719.6: c.2399A > C; p.Lys800Thr). This mutation was found only once in control databases; the mutated lysine is located in the Cav1.2 calcium channel, is highly conserved during evolution, and is predicted to affect protein function by most pathogenicity prediction algorithms. L-type Cav1.2 calcium channels are widely expressed in the brain and heart. In the case presented, electrophysiological studies revealed a prominent reduction in the current amplitude without changes in the gating behavior of the Cav1.2 channel, most likely due to a trafficking defect. Due to the demonstrated loss of function, the p.Lys800Thr variant was finally classified as pathogenic (ACMG class 4 variant) and is likely to cause a newly described Cav1.2 channelopathy.

The Clinical and Molecular Spectrum of GM1 Gangliosidosis.

OBJECTIVE: To evaluate the clinical presentation of patients with GM1 gangliosidosis and to determine whether specific clinical or biochemical signs could lead to a prompt diagnosis. STUDY DESIGN: We retrospectively analyzed clinical, biochemical, and genetic data of 22 patients with GM1 gangliosidosis from 5 metabolic centers in Germany and Austria. RESULTS: Eight patients were classified as infantile, 11 as late-infantile, and 3 as juvenile form. Delay of diagnosis was 6 ± 2.6 months in the infantile, 2.6 ± 3.79 years in the late-infantile, and 14 ± 3.48 years in the juvenile form. Coarse facial features, cherry red spots, and visceromegaly occurred only in patients with the infantile form. Patients with the late-infantile and juvenile forms presented with variable neurologic symptoms. Seventeen patients presented with dystonia and 14 with dysphagia. Laboratory analysis revealed an increased ASAT concentration (13/20), chitotriosidase activity (12/15), and pathologic urinary oligosaccharides (10/19). Genotype analyses revealed 23 causative or likely causative mutations in 19 patients, 7 of them being novel variants. In the majority, a clear genotype-phenotype correlation was found. CONCLUSIONS: Diagnosis of GM1 gangliosidosis often is delayed, especially in patients with milder forms of the disease. GM1 gangliosidosis should be considered in patients with progressive neurodegeneration and spastic-dystonic movement disorders, even in the absence of visceral symptoms or cherry red spots. ASAT serum concentrations and chitotriosidase activity may be of value in screening for GM1 gangliosidosis.

Small supernumerary marker chromosome 15 and a ring chromosome 15 associated with a 15q26.3 deletion excluding the IGF1R gene.

Array comparative genomic hybridization is essential in the investigation of chromosomal rearrangements associated with epilepsy, intellectual disability, and dysmorphic features. In many cases deletions, duplications, additional marker chromosomes, and ring chromosomes originating from chromosome 15 lead to abnormal phenotypes. We present a child with epilepsy, cardiac symptoms, severely delayed mental and growth development, behavioral disturbances and characteristic dysmorphic features showing a ring chromosome 15 and a small supernumerary marker chromosome. Array CGH detected a 1 Mb deletion of 15q26.3 in a ring chromosome 15 and a 2.6 Mb copy number gain of 15q11.2 corresponding to a small supernumerary marker chromosome involving proximal 15q. Our findings add to previously published results of 15q11q13 duplications and 15q26 terminal deletions. Based on our study we can support the previous reported limited information about the role of SELS, SNRPA1, and PCSK6 genes in the development of the heart morphology. On the other hand, we found that the copy number loss of our patient did not involve the IGF1R gene which is often associated with growth retardation (short stature and decreased weight). We hypothesize that haploinsufficiency of the 15q26 genomic region distal to IGF1R gene might be related to growth disturbance; however, presence of the ring chromosome 15 itself could also be responsible for the growth delay.

Novel phenotypic variant in the MYH7 spectrum due to a stop-loss mutation in the C-terminal region: a case report.

BACKGROUND: Defects of the slow myosin heavy chain isoform coding MYH7 gene primarily cause skeletal myopathies including Laing Distal Myopathy, Myosin Storage Myopathy and are also responsible for cardiomyopathies. Scapuloperoneal and limb-girdle muscle weakness, congenital fiber type disproportion, multi-minicore disease were also reported in connection of MYH7. Pathogeneses of the defects in the head and proximal rod region of the protein are well described. However, the C-terminal mutations of the MYH7 gene are less known. Moreover, only two articles describe the phenotypic impact of the elongated mature protein product caused by termination signal loss. CASE PRESENTATION: Here we present a male patient with an unusual phenotypic variant of early-onset and predominant involvement of neck muscles with muscle biopsy indicating myopathy and sarcoplasmic storage material. Cardiomyopathic involvements could not be observed. Sequencing of MYH7 gene revealed a stop-loss mutation on the 3-prime end of the rod region, which causes the elongation of the mature protein. CONCLUSIONS: The elongated protein likely disrupts the functions of the sarcomere by multiple functional abnormalities. This elongation could also affect the thick filament degradation leading to protein deposition and accumulation in the sarcomere, resulting in the severe myopathy of certain axial muscles. The phenotypic expression of the detected novel MYH7 genotype could strengthen and further expand our knowledge about mutations affecting the structure of MyHCI by termination signal loss in the MYH7 gene.

Correction to: Novel phenotypic variant in the MYH7 spectrum due to a stop-loss mutation in the C-terminal region: a case report.

Following publication of the original article [1], the authors requested a correction to the details of one of the co-authors.

[De novo SCN1A gene deletion in therapy-resistant Dravet syndrome]. / De novo SCN1A géndeletio terápiarezisztens Dravet-szindrómában.

Severe myoclonic epilepsy in infancy (Dravet's syndrome) is a very rare form of epilepsy. Mutations of SCN1A gene encoding voltage-gated sodium channel alpha-1 subunit are major causes of the autosomal dominant disorder. Most cases are associated with a de novo point mutation, but some patients have copy number variations. The protein encoded by the SCN1A gene plays a role in the generation and propagation of action potentials. Loss of function caused by the majority of gene mutations leads to hyperexcitability of the neuronal network that finally results in the formation of the epileptic seizures. Molecular genetic test for copy number variations of SCN1A gene is available in the department of the authors since 2013 besides sequencing analysis of the whole gene. This article presents the case of a 7-year-old patient with two years of recorded patient history outside of the author's department. Molecular genetic test, which detected a de novo SCN1A gene deletion in heterozygous form, revealed SCN1A gene associated monogenic epileptic syndrome being in the genetic background of therapy-resistant seizures.

[Genetic testing in hereditary spastic paraplegia]. / Herediter spasticus paraplegia genetikai vizsgálata.

INTRODUCTION: Hereditary spastic paraplegia is the overall term for clinically and genetically diverse disorders characterized with progressive and variable severe lower extremity spasticity. The most common causes of autosomal dominantly inherited hereditary spastic paraplegias are different mutations of the spastin gene with variable incidence in different ethnic groups, ranging between 15-40%. Mutations in the spastin gene lead to loss of spastins function, causing progressive neuronal failure, which results in axon degeneration finally. AIM: The molecular testing of spastin gene is available in the institution of the authors since January, 2014. The experience gained with the examination of the first eleven patients is described in this article. METHOD: After polymerase chain reaction, Sanger sequencing was performed to examine the 17 exons of the spastin gene. Multiplex ligation-dependent probe amplification was performed to detect greater rearrangements in the spastin gene. Eight of the patients were examined in the genetic counseling clinic of the authors and after detailed phenotype assessment spastin gene testing was obtained. The other three patients were referred to the laboratory from different outpatient clinics. RESULTS: Out of the 11 examined patients, four different pathogenic mutations were found in 5 patients. CONCLUSIONS: The first Hungarian data, gained with the examination of spastin gene are presented in this article. The five patients, in whom mutations were detected, represent 45.5% of all tested patients with hereditary spastic paraplegia, which is similar to those published in the international literature. Molecular testing and subsequent detailed genotype-phenotype correlations of the Hungarian patients may serve valuable new information about the disease, which later on may influence our therapeutic possibilities and decisions.

[Attention deficit hyperactivity disorder analyzed with array comparative genome hybridization method. Case report]. / Figyelemhiányos hiperaktivitásban szenvedo beteg vizsgálata array komparatív genomhibridizációs módszerrel.

One of the most common psychiatric disorders during childhood is attention deficit hyperactivity disorder, which affects 5-6% of children worldwide. Symptoms include attention deficit, hyperactivity, forgetfulness and weak impulse control. The exact mechanism behind the development of the disease is unknown. However, current data suggest that a strong genetic background is responsible, which explains the frequent occurrence within a family. Literature data show that copy number variations are very common in patients with attention deficit hyperactivity disorder. The authors present a patient with attention deficit hyperactivity disorder who proved to have two approximately 400 kb heterozygous microduplications at 6p25.2 and 15q13.3 chromosomal regions detected by comparative genomic hybridization methods. Both duplications affect genes (6p25.2: SLC22A23; 15q13.3: CHRNA7) which may play a role in the development of attention deficit hyperactivity disorder. This case serves as an example of the wide spectrum of indication of the array comparative genome hybridization method.

[Identifying rare genomic disorders with array comparative genomic hybridization in Hungary]. / Ritka genomikai betegségek azonosítása array komparatív genomhibridizációs módszerrel - elsoként Magyarországon.

INTRODUCTION: In the past decade the study of genomic disorders has received more interest. Array comparative genome hybridization is a widely spread diagnostic method in the research of genomic disorders. This method was implemented in the laboratory of the authors in 2012. AIM: This molecular cytogenetic method was first used to examine patients with complex developmental disorders in whom no genetic background was identified by traditional methods. METHOD: The authors complemented traditional diagnostic methods with array comparative genome hybridization, which has not been used in routine diagnostics in Hungary so far. RESULTS: Using this novel method the authors were able to identify genomic alterations in 7 out of 18 patients with complex developmental disorders. They found de novo alterations in 6 out of 7 patients, which were most likely causative in the development of the phenotype, while in one case they detected a familial genomic alteration. This method helped the authors to determine the breakpoint of genomic variation in their patients and delineate the affected genes contributing to the phenotype. CONCLUSIONS: These results call attention to the usefulness of next generation diagnostic methods available in the laboratory of the authors.

[Focal dermal hypoplasia associated with pathogenic PORCN gene variant in postzygotic, unilateral mosaic form]. / Fokale dermale Hypoplasie durch pathogene Variante im PORCN-Gen in postzygotischer, unilateraler Mosaik-Konstellation.

We report a case of a 29-year-old woman with subtle partial erythematous, partial hyperpigmented streaks along the Blaschko's lines on the right side of the body since early childhood. Primary DNA results of the skin and blood assay diagnosed focal dermal hypoplasia in mosaic form. The postzygotic mutation in the PORCN gene was only detectable in the affected skin and not in the blood assay. This article illustrates that clinically very discrete hypopigmentation and poikiloderma along Blaschko lines should raise awareness for robust diagnostic analysis in order to recognize this variable multisystem disease and to ensure an appropriate search for extracutaneous abnormalities and human genetic counseling, ideally before pregnancy. Careful correlation of clinical, histological, and genetic features along with close multidisciplinary cooperation of specialists from the fields of human genetics, dermatology, pediatrics, orthopedics and ophthalmology is crucial for final diagnosis, assessment of the prognosis and targeted genetic counseling of affected individuals.

Autosomal Dominant Lamellar Ichthyosis Due to a Missense Variant in the Gene NKPD1.

The identification of monogenic causes for cornification disorders has enhanced our understanding of epidermal differentiation and skin barrier function. Autosomal dominant lamellar ichthyosis is a rare condition, and ASPRV1 was the only gene linked to autosomal dominant lamellar ichthyosis to date. We identified a heterozygous variant (ENST00000686631.1:c.1372G>T, p.[Val458Phe]) in the NKPD1 gene in 7 individuals from a 4-generation German pedigree with generalized lamellar ichthyosis by whole-exome sequencing. Segregation analysis confirmed its presence in affected individuals, resulting in a logarithm of the odds score of 3.31. NKPD1 encodes the NKPD1 protein, implicated in the plasma membrane; its role in human disease is as yet unknown. Skin histology showed moderate acanthosis and compact orthohyperkeratosis, and the ultrastructure differed clearly from that in ASPRV1-autosomal dominant lamellar ichthyosis. Although NKPD1 mRNA expression increased during keratinocyte differentiation, stratum corneum ceramides exhibited no significant changes. However, affected individuals showed an elevated ratio of protein-bound ceramides to omega-esterified ceramides. This highlights NKPD1's role in autosomal dominant lamellar ichthyosis, impacting ceramide metabolism and skin lipid barrier formation, as demonstrated through functional characterization.

Erythrokeratodermia Variabilis-like Phenotype in Patients Carrying ABCA12 Mutations.

Erythrokeratodermia variabilis (EKV) is a rare genodermatosis characterized by well-demarcated erythematous patches and hyperkeratotic plaques. EKV is most often transmitted in an autosomal dominant manner. Until recently, only mutations in connexins such as GJB3 (connexin 31), GJB4 (connexin 30.3), and occasionally GJA1 (connexin 43) were known to cause EKV. In recent years, mutations in other genes have been described as rare causes of EKV, including the genes KDSR, KRT83, and TRPM4. Features of the EKV phenotype can also appear with other genodermatoses: for example, in Netherton syndrome, which hampers correct diagnosis. However, in autosomal recessive congenital ichthyosis (ARCI), an EKV phenotype has rarely been described. Here, we report on seven patients who clinically show a clear EKV phenotype, but in whom molecular genetic analysis revealed biallelic mutations in ABCA12, which is why the patients are classified in the ARCI group. Our study indicates that ARCI should be considered as a differential diagnosis in EKV.

Differences in circulating carnitine status of preterm infants fed fortified human milk or preterm infant formula.

OBJECTIVE: The aim of the study was to compare plasma carnitine profiles in fortified human milk (HM)-fed preterm infants or formula-fed preterm infants. METHODS: Plasma acylcarnitine concentrations were determined in 20 formula-fed and 18 HM-fed preterm infants (birth weights between 1000 and 2200 g) by isotope dilution ESI MS/MS technique on study days 0, 14, and 28. RESULTS: Concentrations of free carnitine (FC) and different acylcarnitines did not change during the 4 weeks of the study in infants fed HM. In contrast, in infants fed formula FC increased markedly (day 0: 29.989 [16.646] µmol/L, median [interquartile range], day 14: 43.972 [8.455], P < 0.05) along with increases of short-chain esters (C2 day 0: 5.300 [3.272], day 14: 6.773 [2.127], P < 0.05; C3 day 0: 0.070 [0.059], day 14: 0.110 [0.069], P < 0.05). In contrast, some medium-chain (C8:1, C12) and long-chain esters (C14, C16) decreased significantly in infant formula by day 14, whereas FC and C2 and C3 esters increased further by day 28 (FC: 47.672 [14.753], C2: 7.430 [4.688], C3: 0.107 [0.047]). CONCLUSIONS: The altered carnitine ester profile likely reflects active involvement of the carnitine molecule in the buffering, metabolism, and elimination of nonphysiological acyl moieties.

Infantile hemangiomas and retinopathy of prematurity: clues to the regulation of vasculogenesis.

UNLABELLED: Retinopathy of prematurity (ROP) and infantile hemangiomas are vascular disorders that may share common mechanisms. This study examined a potential clinical association between these disorders in populations of preterm infants at two hospitals in the USA and Hungary. Clinically collected data from infants with gestational ages less than 32 weeks born between May 1, 2007 and December 31, 2010 seen in the University of Iowa Children's Hospital or the Department of Obstetrics and Gynecology, University of Pécs, were abstracted from electronic medical records and entered into a study database. Demographic and clinical variables were examined as potential covariates to the disorders of interest. Data were initially analyzed by center and then combined through meta-analysis. Six hundred eighty-four subjects were studied: 236 from Pécs and 448 from Iowa. There were no significant demographic differences between populations. Univariate analysis on each study population yielded covariates to ROP in each population, including infantile hemangioma, which were entered into a logistic regression model. These models were combined through random-effects meta-analysis and demonstrated a significant relationship between infantile hemangioma and ROP (odds ratio = 1.84, 95 % confidence interval 1.08-3.12). CONCLUSION: Infantile hemangioma and ROP co-occur in premature infant populations. Further studies are needed to investigate the pathogenesis of both disorders.

[Larsen-syndrome: final diagnosis following multiple surgical interventions]. / Harmincéves betegút után igazolt Larsen-szindróma.

Larsen-syndrome is a rare genetic skeletal dysplasia belonging to the group of actin-binding filamin B associated diseases. The features include congenital dislocations of the large joints, scoliosis and cervical kyphosis, short, broad, spatulate distal phalanges, and distinctive craniofacies. Diagnosis is based on clinical and radiographic findings and confirmed by molecular genetic testing. The authors have performed filamin B molecular genetic analysis since 2005 and have found several cases with unusual phenotypes since. This case report presents the diagnostic difficulties of a 30-year-old woman, who was operated several times with congenital hip dislocations and foot deformities. The craniofacial features, short, broad, spatulate fingers, scoliosis and cervical kyphosis directed diagnosis towards Larsen-syndrome and molecular genetic analysis confirmed a previously-described heterozygous missense mutation (c.G679A). They conclude that genetic analysis performed in time would prevent additional superfluous long diagnostic procedures in patients with rare diseases and would ensure adequate supportive therapy and management of the symptoms.

[Novel TSC1 mutation associated with variable phenotypes in tuberous sclerosis]. / Új TSC1-mutációval társuló variábilis fenotípus sclerosis tuberosában.

Tuberous sclerosis is an autosomal dominant disorder, caused by mutations of the TSC1 or TSC2 genes resulting in tumor predisposition. Clinical signs include non-malignant brain tumors, skin, eye, heart and kidney abnormalities. The authors report a Hungarian family with broad phenotypic variability. First, the 5-year-old boy, showing the most symptoms was examined, whose first seizure occurred at 15 months and a cranial magnetic resonance imaging revealed numerous intracerebral calcareous foci. Except of hypopigmented skin spots, no other abnormality was found on physical examination. The mother was completely asymptomatic. Epilepsy of the maternal uncle started at the age of 3 years, of his sister at the age of 17 years and of the maternal grandmother at the age of 39 years. At the age of 52 years the grandmother developed renal cysts. Molecular genetic analysis of the family confirmed a de novo heterozygous point mutation (c.2524 C\>T) [corrected] in exon 20 of the TSC1 gene. The mutation was detected in all examined family members. Despite increasing data on the pathomechanism of tuberous sclerosis, there is still little known about the genetic modifying factors influencing the broad intra- and interfamilial phenotypic variability.

Syndromic ichthyoses.

Inherited ichthyoses are classified as Mendelian disorders of cornification (MEDOC), which are further defined on the basis of clinical and genetic features and can be divided into non-syndromic and syndromic forms. To date, mutations in more than 30 genes are known to result in various types of syndromic ichthyoses, which, in addition to mostly generalised scaling and hyperkeratosis of the skin, also show additional organ involvement. The syndromic ichthyoses are generally very rare and are classified based on the mode of inheritance, and can be further subdivided according to the predominant symptoms. In our review we provide a concise overview of the most prevalent syndromic forms of ichthyosis within each subgroup. We emphasize the importance of the clinical assessment of complex syndromes even in the era of genetic testing as a first-tier diagnostic and specifically the need to actively assess potential organ involvement in patients with ichthyosis, thereby enabling efficient diagnostic and therapeutic approaches and timely access to specialized centers for rare disorders of cornifications. As part of the Freiburg Center for Rare Diseases a Center for Cornification Disorders was recently established with collaboration of the Institute of Human Genetics and the Department of Dermatology. An early diagnosis of syndromes will be of direct benefit to the patient regarding interventional and therapeutic measures e. g. in syndromes with cardiac or metabolic involvement and allows informed reproductive options and access to prenatal and preimplantation genetic diagnosis in the family.