Radiological characteristics of skeletal growth in neonates and infants with achondroplasia.

Achondroplasia (ACH) is the most common form of skeletal dysplasia characterized by a rhizomelic short stature. Radiological skeletal findings in pediatric and adult patients with ACH include short long bones, a relatively longer fibula compared to the tibia, a narrow lumbar interpedicular distance, and a hypoplastic iliac wing. Nonetheless, the characteristics of skeletal growth during the neonatal and infantile periods have scarcely been explored. Therefore, this retrospective study aimed to analyze the radiological skeletal growth during the neonatal and infantile periods in 41 Japanese patients with genetically confirmed ACH. The length of long bones in the upper and lower limbs and the lumbar interpedicular distances at L1 and L4 were measured. These parameters showed significant positive correlations with age. The upper segment-to-lower segment ratio in the lower limbs resembled the data of healthy controls from previous reports. The L1/L4 and fibula/tibia ratios increased with age, suggesting that some representative skeletal phenotypes of ACH were less distinct during the neonatal and infantile periods. In conclusion, for the first time, this study radiologically characterized skeletal growth during the neonatal and infantile periods of patients with genetically confirmed ACH.

The clinical course of Rathke's cleft cysts in pediatric patients: impact on growth and pubertal development.

Rathke's cleft cysts (RCCs) are non-neoplastic epithelial lesions in the sellar or suprasellar regions. RCCs are usually asymptomatic; however, some patients experience headaches, visual disturbances, and endocrine disorders. The best treatment for associated endocrinopathy remains elusive. We aimed to investigate the clinical course, magnetic resonance imaging findings, and response to therapy in 10 pediatric patients with RCCs and endocrinopathy. Growth impairment and precocious puberty were observed to be prevalent. One patient with suprasellar extension of RCC underwent surgery, while the others were treated medically. Of the nine patients, seven patients showed stable cyst size, while two patients displayed reduction in cyst size. Hormone replacement and gonadotropin suppression therapy were found to be effective. Imaging and endocrine follow-ups are warranted because of the potential for changes in the cyst size and hormonal changes.

A novel pathogenic variant p.Asp797Val in IFIH1 in a Japanese boy with overlapping Singleton-Merten syndrome and Aicardi-Goutières syndrome.

Pathogenic-activating variants of interferon induced with Helicase C domain 1 (IFIH1) cause Singleton-Merten (S-M) syndrome, which accompanies acro-osteolysis, loss of permanent teeth, and aortic calcification, as well as causing Aicardi-Goutières (A-G) syndrome, which shows progressive encephalopathy, spastic paraplegia, and calcification of basal ganglia. Recently, patients with overlapping syndromes presenting with features of S-M syndrome and A-G syndrome were reported. However, progression of clinical features of this condition has not been fully understood. We report a Japanese boy with a novel pathogenic IFIH1 variant who presented with clinical features of S-M syndrome and A-G syndrome.

Sorafenib treatment for papillary thyroid carcinoma with diffuse lung metastases in a child with autism spectrum disorder: a case report.

BACKGROUND: Pediatric papillary thyroid carcinoma frequently presents with lymph node involvement and distant metastases. Sorafenib, an oral multikinase inhibitor, has been used to treat radioactive iodine (RAI) therapy-refractory thyroid carcinoma in adults; however, pediatric experience is limited. Medical procedures and hospitalization for children with autism spectrum disorder may be challenging. CASE PRESENTATION: An 11-year-old boy with autism spectrum disorder and moderate intellectual impairment presented with dyspnea on exertion with thyroid carcinoma and diffuses lung metastases. Total thyroidectomy and adjuvant RAI therapy is the standard treatment; however, the latter therapy was impractical because of his respiratory status and challenging behaviors. He was therefore started on sorafenib 200 mg/day (150 mg/m2/day) and this dosage was increased to 400 mg/day (300 mg/m2/day). The adverse effects were mild and tolerable. After administration of medication, his dyspnea improved and surgery was performed. We attempted to administer RAI therapy after surgery; however, we abandoned it because he had difficulty taking care of himself according to isolation room rules. Thyrotropin suppression therapy was therefore started and sorafenib treatment (400 mg/day) resumed. Follow-up imaging showed regression of pulmonary metastases. The metastases have remained stable for over 24 months on continuous sorafenib treatment without serious adverse events. CONCLUSION: We inevitably used sorafenib as an alternative to standard therapy because of the patient's specific circumstances. Individualized strategies for pediatric cancer patients with autism spectrum disorder are needed.

A novel mutation in the COL2A1 gene in a patient with Stickler syndrome type 1: a case report and review of the literature.

BACKGROUND: Stickler syndrome is a group of collagenopathies characterized by ophthalmic, skeletal, and orofacial abnormalities, with the degree of symptoms varying among patients. Mutations in the COL2A1, COL11A1, and COL11A2 procollagen genes cause Stickler syndrome. Marshall syndrome, caused by a COL11A1 mutation, has clinical overlap with Stickler syndrome. CASE PRESENTATION: A 2-year-old Japanese boy was presented to our hospital with short stature (79.1 cm, -2.52 standard deviation). His past medical history was significant for soft cleft palate and bilateral cataracts. He had a flat midface, micrognathia, and limitations in bilateral elbow flexion. Radiographs showed mild spondyloepiphyseal dysplasia. Initially, we suspected Marshall syndrome, but no mutation was identified in COL11A1. At 8 years old, his height was 116.2 cm (-1.89 standard deviation), and his orofacial characteristics appeared unremarkable. We analyzed the COL2A1 gene and found a novel heterozygous mutation (c.1142 G > A, p.Gly381Asp). CONCLUSIONS: In this case report, we identify a novel missense mutation in the COL2A1 gene in a patient with Stickler syndrome type 1, and we describe age-related changes in the clinical phenotype with regard to orofacial characteristics and height. Genetic analysis is helpful for the diagnosis of this clinically variable and genetically heterogeneous disorder.

Three cases of Japanese acromicric/geleophysic dysplasia with FBN1 mutations: a comparison of clinical and radiological features.

Acromicric dysplasia (AD) and geleophysic dysplasia (GD) are rare skeletal dysplasias characterized by short stature, acromelia, joint contracture, hepatomegaly, hoarseness and respiratory distress. Compared with GD, AD presents with milder clinical and radiological features. Radiological findings of AD and GD consist of shortened tubular bones of the hands and feet, and deformed capital femoral epiphyses. The genetic cause of AD and some cases of GD was shown to be mutations in the transforming growth factor (TGF) ß-binding protein-like domain 5 of the fibrillin 1 gene (FBN1), which is also mutated in Marfan syndrome. In the present study, we report and compare the highly varied clinical and radiological features of three Japanese AD/GD children. Our patients, harboring FBN1 mutations p.Tyr1699Cys, p.Ser1750Arg, and p.Gly1762Ser, shared common clinical symptoms such as severe short stature, acromelia and hepatomegaly. Short tubular bones of hands and deformities of femur heads are common radiological features of our patients.

Urinary Cross-linked N-terminal Telopeptide of Type I Collagen Levels of Infants with Osteogenesis Imperfecta and Healthy Infants.

The urinary cross-linked N-terminal telopeptide of type I collagen (uNTx) levels in infantile osteogenesis imperfecta (OI) have not been well studied. Here we investigated the levels of uNTx in infants with OI and healthy infants. We collected spot urine samples from 30 infants with OI (male/female, 14/16; Sillence classification, I/II/III/IV: 15/3/6/6; age, 5.2±4.4 months) and 120 healthy infants (male/female, 75/45; age, 5.1±4.1 months) for the measurement of uNTx levels. The uNTx levels of the OI infants were significantly lower than those of the healthy infants (mean±SD, 1,363.7±530.1 vs. 2,622.2±1,202.6 nmol BCE/mmol Cr; p＜0.001). The uNTx levels of the infants with type I OI were significantly lower than those of the age-matched healthy infants, although an overlap was observed between the 2 groups. Among the 1-month-old infants, the uNTx levels of the infants with types I, III or IV OI were significantly lower than those of the healthy infants, without overlap (1,622.5±235.8 vs. 3,781.0±1,027.1 nmol BCE/mmol Cr; p＜0.001). These results indicate that uNTx levels are significantly lower in infants with OI than in healthy infants, and they suggest that uNTx might be useful as a reference for diagnosing OI.

HDR syndrome in a Japanese girl with biliary atresia: a case report.

BACKGROUND: Hypoparathyroidism, sensorineural deafness, and renal dysplasia (HDR) syndrome is an autosomal dominant disorder. We report the first detailed case of hypoparathyroidism complicated by biliary atresia. CASE PRESENTATION: A 1-year-old Japanese girl was admitted to our hospital for living donor liver transplantation. She suffered from obstructive jaundice owing to biliary atresia. She also had persistent hypocalcemia. Despite oral calcium and abundant vitamin D supplementation, a laboratory test showed hypocalcemia (1.4 mmol/l) and hyperphosphatemia (2.6 mmol/l). The intact parathyroid hormone level was normal (66 ng/l) with severe vitamin D deficiency (25-hydroxy vitamin D: undetectable levels). There were no rachitic changes in metaphysis on X-rays. Her family history showed that her mother had sensorineural deafness, a low serum calcium level (2.1 mmol/l), hypoplastic left kidney, and a past history of an operation for right vesicoureteral reflux. We suspected that this patient and her mother have hypoparathyroidism, sensorineural deafness, and renal dysplasia syndrome. A heterozygous GATA3 gene mutation (c.736delGinsAT) was found in this patient and her mother, but not in her father. CONCLUSION: This familial case confirms the importance of family history in the diagnosis of HDR syndrome. Regardless of marked vitamin D deficiency, the complication of hypoparathyroidism prevented the onset of vitamin D deficiency rickets in our patient.