FBN1 gene mutation in a Chinese pedigree of mild Geleophysic dysplasia type 2/Acromicric dysplasia and the exploration of growth-promoting therapy / 中华内分泌代谢杂志

Objective:To summarize the clinical and genetic features of 7 patients with a mild form of Geleophysic dysplasia type 2(GD2)/Acromicric dysplasia(AD) induced by fibrillin 1(FBN1) gene mutation from one Chinese family.Methods:A Chinese pedigree of mild GD2/AD treated at the Pediatric Endocrinology Department at the First Affiliated Hospital of Sun Yat-sen University between August 2017 and May 2022 was collected. Whole-exome genetic sequencing of the FBN1 gene were performed to establish the diagnosis. Additionally, a literature review was further conducted.Results:In this family, among 13 individuals spanning three generations, there were 7 affected cases, including 1 adult female, 1 adult male, and 5 children. All individuals exhibited postnatal growth failure, severe disproportionate short stature, and lacked typical facial features. Exome sequencing and Sanger sequencing confirmed the presence of a heterozygous missense mutation c. 5099A>G(p.Tyr1700Cys) in exon 42 of the FBNI gene in 6 affected individuals(Ⅱ-1, Ⅲ-1 to Ⅲ-5), which was identified as a pathogenic mutation. This mutation was previously reported in a Chinese classical achondroplasia(AD) family. Based on comprehensive genetic analysis, clinical features, and multisystem evaluation, 3 cases were diagnosed with mild type 2 growth hormone deficiency(GD2), and 4 cases were diagnosed with mild AD. Recombinant human growth hormone(rhGH; 1.1-1.4 IU·kg -1·week -1) was applied to all the 5 children, and additional gonadotropin releasing hormone analogue(GnRHa) was administered to the 2 girls in late puberty, resulting in certain growth-promoting effect. Conclusions:The c. 5099A>G(p.Tyr1700Cys) mutation not only leads to the classical type of achondroplasia(AD) as reported in the literature but also causes the non-classical GD2 or AD(mild GD2/AD). Further research is warranted to investigate the long-term therapeutic effects of rhGH treatment.

Advances in acromelic dysplasia caused by FBN1 mutation / 国际儿科学杂志

The mutation of FBN1 gene results in the abnormality of its encoded fibrillin-1 protein, which affects musculoskeletal growth and results in two opposing phenotypes of tall and short stature, with clinical manifestations of Marfan syndrome and acromelic dysplasia.Acromelic dysplasia caused by FBN1 mutation includes acromicric dysplasia(AD), geleophysic dysplasia(GD)and Weill-Marchesani syndrome(WMS). As some FBN1 mutations have been reported to cause both AD and GD.The dysregulation of TGF-β signal pathway is the underlying mechanism of acromelic dysplasia.Currently, there is no specific treatment, mainly symptomatic treatment, early identification, diagnosis and treatment will improve prognosis of patients.This article will review the pathogenesis, clinical phenotype, treatment and follow-up of acromelic dysplasia caused by FBN1 mutation.

Valve Replacement for Progressive Mitral Valve Stenosis Associated with Geleophysic Dysplasia / 日本心臓血管外科学会雑誌

The patient was an 8-years- and 4-months old girl. At the age of one, she visited a previous doctor with hepatomegaly and liver dysfunction. As a result of the examination, she was diagnosed with geleophysic dysplasia. Other than the heart, she was followed in genetics, ophthalmology, orthopedics, endocrinology, and otolaryngology. At 3 years and 5 months, she was first examined by the cardiology department and was found to have mild mitral regurgitation and aortic valve stenosis, and was followed up once a year. The patient was referred to our hospital at 7 years and 11 months, and the cardiac catheterization performed at 8 years and 2 months showed mild mitral valve regurgitation, but the mean pressure gradient was 16 mmHg and the mitral valve area was 0.60 cm2 (MVAi 0.97 cm2/m2), and mitral valve stenosis was observed. The left atrial pressure was as high as 25 mmHg and the average pulmonary artery pressure was as high as 36 mmHg, and pulmonary hypertension was also observed. Intraoperative findings demonstrated that the mitral valve had a marked thickening of the leaflet, the papillary muscles and chordae were also thickened, and the effective valve opening area was narrowed. The leaflet and subvalvular tissue were resected as much as possible and mechanical valve replacement was performed. Postoperatively, the patient recovered satisfactorily and was discharged on the 16th postoperative day. Pathological findings showed no major disturbance in the layered structure of the papillary muscle or the leaflet itself, but it was highly thickened due to mucous degeneration of the leaflet. We report our experience with the rare case described above.

Geleophysic dysplasia associated with bilateral angle closure glaucoma.

In this case report, we present occurrence of bilateral angle closure glaucoma in a 9-year-old girl with geleophysic dysplasia. Bilateral YAG laser iridotomy was applied, but intraocular pressure (IOP) remained at high levels, necessitating bilateral trabeculectomy with mitomycin C. On her follow-up examinations for 3 years, IOP remained in the mid-20s with no need for further intervention or antiglaucoma medication. There are few reports describing the ocular findings of geleophysic dysplasia in literature. To our knowledge, this is the first case report describing an application of glaucoma surgery and its results at geleophysic dysplasia.