Two novel mutations in TCIRG1 induced infantile malignant osteopetrosis: a case report.

BACKGROUND: Infantile malignant osteopetrosis (IMO) is a rare autosomal recessive disease characterized by a higher bone density in bone marrow caused by the dysfunction of bone resorption. Clinically, IMO can be diagnosed with medical examination, bone mineral density test and whole genome sequencing. CASE PRESENTATION: We present the case of a 4-month-old male infant with abnormal skull development, hypocalcemia and premature closure of the cranial sutures. Due to the hyper bone density showed by his radiographic examination, which are characteristic patterns of IMO, we speculated that he might be an IMO patient. In order to confirm this diagnosis, a high-precision whole exome sequencing of the infant and his parents was performed. The analysis of high-precision whole exome sequencing results lead to the identification of two novel heterozygous mutations c.504-1G > C (a splicing site mutation) and c.1371delC (p.G458Afs*70, a frameshift mutation) in gene TCIRG1 derived from his parents. Therefore, we propose that there is a close association between these two mutations and the onset of IMO. CONCLUSIONS: To date, these two novel mutations in gene TCIRG1 have not been reported in the reference gene database of Chinese population. These variants have likewise not been reported outside of China in the Genome Aggregation Database (gnomAD). Our case suggests that the use of whole exome sequencing to detect these two mutations will improve the identification and early diagnosis of IMO, and more specifically, the identification of homozygous individuals with TCIRG1 gene mutation. We propose that these mutations in gene TCIRG1 could be a novel therapeutic target for the IMO in the future.

Effect of bronchopulmonary dysplasia on early intellectual development in preterm infants.

BACKGROUND: The aim of this study was to investigate the effect of bronchopulmonary dysplasia (BPD) on the early intellectual development of preterm infants. METHODS: From 2011 to 2015, 83 preterm infants diagnosed with BPD were recruited to the BPD group, and 89 preterm infants without BPD and 98 healthy term infants were randomly recruited to the non-BPD and term group, respectively. Neural and intellectual development according to the Gesell Development Scale were evaluated and compared between groups at 0-3 months, 3-6 months, 6-9 months, and 9-12 months of adjusted age for preterm infants and real age for term infants. Multivariate logistic regression was used to determine the associations between BPD and adverse neurological outcomes at 9-12 months of adjusted age. RESULTS: Compared with term infants, preterm infants had significantly lower developmental quotients for adaptability, gross motor, fine motor, language and social skills. At follow up, deficits in one or more neurofunctions related to adaptability, gross motor, fine motor, language and social skills were significantly more frequent in preterm children with BPD than in those with no history of BPD. BPD was independently associated with adverse neurological outcome at 9-12 months of adjusted age in preterm infants. CONCLUSIONS: Early intelligence disturbances occurred significantly more frequently in BPD infants than in non-BPD infants. Monitoring of the development of the nervous system in BPD infants should be strengthened.