Consensus recommendations on organization of care for individuals with Phelan-McDermid syndrome.

The manifestations of Phelan-McDermid syndrome (PMS) are complex, warranting expert and multidisciplinary care in all life stages. In the present paper we propose consensus recommendations on the organization of care for individuals with PMS. We indicate that care should consider all life domains, which can be done within the framework of the International Classification of Functioning, Disability and Health (ICF). This framework assesses disability and functioning as the outcome of the individual's interactions with other factors. The different roles within care, such as performed by a centre of expertise, by regional health care providers and by a coordinating physician are addressed. A surveillance scheme and emergency card is provided and disciplines participating in a multidisciplinary team for PMS are described. Additionally, recommendations are provided for transition from paediatric to adult care. This care proposition may also be useful for individuals with other rare genetic neurodevelopmental disorders.

The MECP2 variant c.925C>T (p.Arg309Trp) causes intellectual disability in both males and females without classic features of Rett syndrome.

Missense MECP2 variants can have various phenotypic effects ranging from a normal phenotype to typical Rett syndrome (RTT). In females, the phenotype can also be influenced by the X-inactivation pattern. In this study, we present detailed clinical descriptions of six patients with a rare base-pair substitution affecting Arg309 at the C-terminal end of the transcriptional repression domain (TRD). All patients have intellectual disability and present with some RTT features, but they do not fulfill the clinical criteria for typical or atypical RTT. Most of the patients also have mild facial dysmorphism. Intriguingly, the mother of an affected male patient is an asymptomatic carrier of this variant. It is therefore likely that the p.(Arg309Trp) variation does not necessarily lead to male lethality, and it results in a wide range of clinical features in females, probably influenced by different X-inactivation patterns in target tissues.

Mutations of the apolipoprotein A5 gene with inherited hypertriglyceridaemia: review of the current literature.

Apoliporotein A5 (APOA5), a member of the apolipoprotein family, plays a key regulatory role in triglyceride (TG) metabolism. Even though the exact biochemical background of its mechanism is not yet fully understood, diseases associated with this particular gene highlighted its key role in the metabolism of triglycerides in humans. Naturally occurring functional variants of the gene and their natural major haplotypes are known to associate with moderately elevated triglyceride levels, and are also known to confer risk or protection for major polygenic diseases, like coronary heart disease, stroke, or metabolic syndrome. On the other hand, case reports and even robust resequencing studies verified APOA5 mutations as underlying genetic defects behind extreme hypertriglyceridemic phenotype. Soon after the recognition of the first cases, there were indications which suggest the existence of less frequent genetic variants which, in combination with the common allelic variants of the gene, can define haplotypes that are associated with substantial triglyceride level increase. In addition, it became evident, that there are rare mutations of the APOA5 gene which can be associated with specific complex phenotypes and different types of hyperlipoproteinemia, which includes extremely high triglyceride levels with multiple organ pathology. These rare mutations may cause inheritable hypertriglyceridemia, but they presented at a low frequency and could not be captured by standard genotyping array screenings. The identification of new mutations still relies on the direct sequencing of APOA5 gene of patients with hypertriglyceridemia with an unusual pattern, individually or in huge resequencing studies.

Mutational spectrum of smith-lemli-opitz syndrome patients in hungary.

Smith-Lemli-Opitz (SLO) syndrome is an autosomal recessive disorder characterized by multiple congenital abnormalities and mental retardation. The condition is caused by the deficiency of 7-dehydrocholesterol reductase (DHCR7) which catalyzes the final step in cholesterol biosynthesis. Biochemical diagnosis is based on increased concentration of 7-dehydrocholesterol (7-DHC) in the patient serum. Both life expectancy and quality of life are severely affected by the disease. The estimated prevalence of SLO syndrome ranges between 1:20,000 and 1:40,000 among Caucasians. Although the mutational spectrum of the disease is wide, approximately 10 mutations are responsible for more than 80% of the cases. These mutations show a large interethnic variability. There are no mutation distribution data from Hungary to date. Thirteen patients were diagnosed with SLO syndrome in our laboratory. As first-line tests, serum 7-DHC and total cholesterol were measured and, in positive cases, molecular genetic analysis of the DHCR7 gene was performed. Complete genetic background of the disease could be identified in 12 cases. In 1 case only 1 mutation was detected in a heterozygote form. One patient was homozygous for the common splice site mutation c.964-1G>C, while all other patients were compound heterozygotes. One novel missense mutation, c.374A>G (p.Tyr125Cys) was identified.

Congenital disorder of glycosylation type Ix: review of clinical spectrum and diagnostic steps.

Congenital disorder of glycosylation type I (CDG I) represent a rapidly growing group of inherited multisystem disorders with 13 genetically established subtypes (CDG Ia to CDG Im), and a high number of biochemically unresolved cases (CDG Ix). Further diagnostic effort and prognosis counselling are very challenging in these children. In the current study, we reviewed the clinical records of 10 CDG Ix patients and compared the data with 13 CDG Ix patients published in the literature in search for specific symptoms to create clinical subgroups. The most frequent findings were rather nonspecific, including developmental delay and axial hypotonia. Several features were found that are uncommon in CDG syndrome, such as elevated creatine kinase or arthrogryposis. Distinct ophthalmological abnormalities were observed including optic nerve atrophy, cataract and glaucoma. Two subgroups could be established: one with a pure neurological presentation and the other with a neurological-multivisceral form. The first group had a significantly better prognosis. The unique presentation of microcephaly, seizures, ascites, hepatomegaly, nephrotic syndrome and severe developmental delay was observed in one child diagnosed with CDG Ik. Establishing clinical subgroups and increasing the number of patients within the subgroups may lead the way towards the genetic defect in children with a so far unsolved type of the congenital disorders of glycosylation. Raising awareness for less common, non-CDG specific clinical features such as congenital joint contractures, movement disorders or ophthalmological anomalies will encourage clinicians to think of CDG in its more unusual presentation. Clinical grouping also helps to determine the prognosis and provide better counselling for the families.

Hyponatremia and sensorineural hearing loss in preterm infants.

In a case-control study the role of hyponatremia in the hearing loss of preterm infants was investigated. One hundred and sixty-four premature infants treated at the neonatal intensive care unit were screened with transient evoked otoacoustic emission (TEAOE). In 32 infants TEAOE results indicated the need for further investigations. Auditory brainstem response was performed and 22 of 32 cases had bilateral hearing impairment (HI). The birth weight and gestational age in the HI group were 1,425 +/- 528 g and 30.4 +/- 3.7 weeks. The matched control group consisted of 25 infants with a mean birth weight and gestational age of 1,410 +/- 280 g and 31.1 +/- 2.1 weeks. Significant differences were found between the HI and control groups: Apgar score (p < 0.05), pH value (p < 0.01) and pO(2) level (p < 0.05) were lower; the total dose of aminoglycosides (p < 0.01), furosemide usage (p < 0.01), the maximum pCO(2) level (p < 0.01), incubator stay (p < 0.05) and hyponatremia (p < 0.01) were higher, and the duration of hyponatremia (p < 0.05) was longer in the HI group. Multivariate logistic regression revealed that aminoglycoside treatment and hyponatremia were the two most significant factors in the development of hearing impairment. These results suggest that hyponatraemia is an additional risk factor for hearing loss in preterm infants.