Assessment and Treatment of Self-Injurious Behavior Associated with Donnai-Barrow Syndrome

Behavioral Phenotype, Electroclinical Features, and Treatment Options in Twins with Lrp2 Candidate Variants (Donnay-Barrow/Foar Syndrome)

The LRP2 gene encodes megalin (LRP-2/GP330), a large single-spanning transmembrane glycoprotein that serves as a multiligand endocytotic receptor and mediates the reabsorption of albumin in the proximal renal tubule. LRP2 is implicated in an autosomal recessive disorder characterized by dimorphisms, ocular anomalies, sensorineural deafness, proteinuria, epilepsy, and intellectual disability: a clinical condition called Donnai-Barrow syndrome (DBS) or facio-oculo-acoustico-renal (FOAR) syndrome. Pathogenic variants in LRP2 have been reported in fewer than 60 patients, but a detailed description of seizures, electroencephalographic patterns, imaging findings, behavioral phenotype, and long-term follow-up is still needed. We provide a clinical report of two mono-chorionic twins with LRP2-related disease manifesting developmental delay, autistic features, seizures, proteinuria, and sleep disorders. By sequencing clinical exome, LRP2 candidate rare variants, c.6815G > A, p. (Arg2272His), inherited from the mother and c.12725A > G, p. (Asp4242Gly), inherited from the father, were identified. During follow-up, at the age of 7, the main clinical features of the patients included insomnia, autistic features, severe psychomotor delay, and absent speech. The patients were under treatment with risperidone, antiseizure medications (ASMs), and supplementation of alpha-lactalbumin for self-injury and sleep disturbance. Our study confirmed the wide spectrum of behavioral and neurological and psychiatric features of this rare condition, suggesting new treatment options.

Two novel variations in LRP2 cause Donnai-Barrow syndrome in a Chinese family with severe early-onset high myopia

Donnai-Barrow syndrome (DBS) is a rare autosomal recessive disorder caused by mutation in the low density lipoprotein receptor-related protein 2 gene (LRP2). Defects in this protein may lead to clinical multiple organ malformations by affecting the development of organs such as the nervous system, eyes, ears, and kidneys. Although some variations on LRP2 have been found to be associated with DBS, early diagnosis and prevention of patients with atypical DBS remains a challenge for many physicians because of their clinical heterogeneity. The objective of this study is to explore the association between the clinical presentation and the genotype of a DBS patient who was initially diagnosed with early-onset high myopia (eoHM) from a healthy Chinese family. To this end, we tested the patient of this family via whole exome sequencing and further verified the results among other family members by Sanger sequencing. Comprehensive ophthalmic tests as well as other systemic examinations were also performed on participants with various genotypes. Genetic assessment revealed that two novel variations in LRP2, a de novo missense variation (c.9032G>A; p.Arg3011Lys) and a novel splicing variation (c.2909-2A>T) inherited from the father, were both carried by the proband in this family, and they are strongly associated with the typical clinical features of DBS patients. Therefore, in this paper we are the first to report two novel compound heterozygous variations in LPR2 causing DBS. Our study extends the genotypic spectrums for LPR2-DBS and better assists physicians in predicting, diagnosing, and conducting gene therapy for DBS.

A Case Report of Donnai-Barrow Syndrome

BACKGROUND

A genetic disorder should be considered when an infant presents with multiple congenital anomalies. Because of the acute presentation of an infant with multiple life-threatening defects, a genetic diagnosis of a rare disorder took weeks to delineate.

CLINICAL FINDINGS

This case describes a late preterm infant who presented at birth with congenital diaphragmatic hernia, tetralogy of Fallot, cleft lip, low-set ears, and hypertelorism.

PRIMARY DIAGNOSIS

Donnai-Barrow syndrome was the final diagnosis confirmed by a defect observed on the LRP2 (2q31.1) gene using sequence analysis. This is a rare disorder that presents with a variety of phenotypic features in infants.

INTERVENTIONS

Initial neonatal resuscitation in the delivery room included intubation, positive pressure ventilation, and oxygen supplementation. Extracorporeal membrane oxygenation therapy was initiated from day of life 3 to 15. Initial surgery included correction of the congenital diaphragmatic hernia, and further surgical procedures included tracheostomy, gastrostomy tube, circumcision, ventricular septal defect repair, and cleft lip repair. Physical, occupational, and speech therapies were also initiated.

OUTCOMES

The infant was transported to a pediatric rehabilitation facility at 6 months of life for further management of his chronic lung disease requiring tracheostomy with ventilator dependence.

PRACTICE RECOMMENDATIONS

Early recognition and diagnosis of genetic syndromes can improve family education and guide treatment interventions. An underlying syndrome should be suspected when an infant presents with multiple congenital defects. Infants with Donnai-Barrow syndrome should have thorough cardiac, neurologic, ophthalmologic, audiologic, and renal examinations due to the gene mutation effects on those systems.

Prevention and early intervention for behaviour problems in children with developmental disabilities

PURPOSE OF REVIEW

To review the recent evidence regarding early intervention and prevention studies for children with developmental disabilities and behaviour problems from 2011 to 2013. Recent advances in the field are discussed and important areas for future research are highlighted.

RECENT FINDINGS

Recent reviews and studies highlight the utility of antecedent interventions and skills training interventions for reducing behaviour problems. There is preliminary evidence for the effectiveness of parent training interventions when delivered in minimally sufficient formats or in clinical settings. Two recent studies have demonstrated the utility of behavioural interventions for children with genetic causes of disability.

SUMMARY

Various forms of behavioural and parent training interventions are effective at reducing the behaviour problems in children with developmental disabilities. However, research on prevention and early intervention continues to be relatively scarce. Further large-scale dissemination studies and effectiveness studies in clinical or applied settings are needed.