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Homocystinuria
Published in William L. Nyhan, Georg F. Hoffmann, Aida I. Al-Aqeel, Bruce A. Barshop, Atlas of Inherited Metabolic Diseases, 2020
William L. Nyhan, Georg F. Hoffmann, Aida I. Al-Aqeel, Bruce A. Barshop
Homocystinuria represents a multisystem disorder with involvement of the eyes, integument, skeleton, vascular system, and nervous system [4, 6, 7]. Patients are born normal but in the untreated, severe form they develop the full constellation of clinical abnormalities within 2–6 years of life. Ectopia lentis is a striking and readily recognizable manifestation of the disease (Figures 18.2–18.5). It is often preceded by rapidly worsening myopia, which may be the only manifestation [4–8] and, by 38 years of age, only 3 percent of patients have both lenses in place. Dislocation is usually present by ten years of age. The dislocation is said to be usually, but not always, downward – the opposite of the situation in Marfan disease. Its presence may be signaled by iridodonesis, a dancing or shimmering of the iris. Electron microscopy reveals partially broken zonules, abnormal zonular attachment, and a spongy capsular appearance [8]. Complications may include dislocation into the anterior chamber and papillary block glaucoma (Figure 18.3). Other ocular abnormalities include myopia, optic atrophy, cataracts, or retinal detachment [9].
Ophthalmology
Published in Shibley Rahman, Avinash Sharma, A Complete MRCP(UK) Parts 1 and 2 Written Examination Revision Guide, 2018
Shibley Rahman, Avinash Sharma
Ectopia lentis/subluxation of the lens is associated with: Ehlers-Danlos syndromeMarfan’s syndromeWeill-Marchesani syndrome (short stature, skeletal abnormalities and ectopia lentis)Refsuiris diseasehomocystinuria
Section 9
Published in Padmanabhan Ramnarayan, MCQs in Paediatrics for the MRCPCH, Part 1, 2017
Marfan syndrome is an autosomal dominant inherited disease. There is increased limb length and arachnodactyly. Eye anomalies include ectopia lentis and myopia. Mitral valve prolapse, aortic régurgitation and dissecting aneurysms are seen. Cognitive impairment is seen in homocystinuria, not in Marian's.
Pre-implantation genetic testing for Marfan syndrome using mini-sequencing
Published in Journal of Obstetrics and Gynaecology, 2022
Sirivipa Piyamongkol, Krit Makonkawkeyoon, Vorasuk Shotelersuk, Opas Sreshthaputra, Tawiwan Pantasri, Rekwan Sittiwangkul, Theera Tongsong, Wirawit Piyamongkol
Marfan syndrome (MFS1, OMIM#154700) is the most common connective tissue disorder. MFS1 is inherited in an autosome dominant manner. Its incidence is about 2–3 in 10,000. It was first clinically described in 1896 (Marfan 1896). Major phenotypes include skeletal, ocular and cardiovascular system involvement. Anterior chest and vertebral column deformity, disproportionately tall stature, arachnodactyly and joint laxity are common skeletal manifestations. Ectopia lentis is a key ocular characteristic. Cardiovascular manifestations are the leading cause of the morbidity and mortality associated with Marfan syndrome. Aortopathy, i.e. aortic root dilatation, aortic regurgitation secondary from aortic dilatation, and fatal aortic dissection are the major causes. A family history of aortic dissection is the most important predicting factor for the risk of aortic dissection in affected offspring (Pyeritz 1993).
Double decentred lenses in an eye: a therapeutic dilemma in Marfan syndrome
Published in Clinical and Experimental Optometry, 2020
Wei‐shan Tsai, Yuan‐chieh Lee, Fang‐ling Chang, Ming‐shan He
Marfan syndrome occurs in one in 5,000 children. It is an autosomal dominant disorder that mainly affects the connective tissue. It is caused by the mutation of the fibrillin‐1 gene (FBN1) and subsequently results in elastic fibre malformation.1991 Ectopia lentis was found to be the most common ocular complication, which significantly affects vision.2017 The abnormal fibrillin‐related loose zonules in Marfan syndrome allow the crystalline lens to become more spherical and to decentre relative to the visual axis. Typically, the most common refractive error in Marfan syndrome is high myopia resulting from microspherophakia and longer axial length. The patient in this case received bilateral anterior chamber intraocular lens implantation at another clinic to correct her high myopia. Nevertheless, an anterior chamber intraocular lens implantation in a patient with Marfan syndrome may have a higher risk of intraocular lens decentring due to the unusually deep and large anterior chamber anatomy. Diplopia occurred when the light was bisected simultaneously by the subluxated natural lens and the decentred anterior chamber intraocular lens. Thus, a phenomenon of ‘double decentred lenses in an eye’ was observed in our patient. Therefore anterior chamber intraocular lens implantation alone without removal of the subluxated natural lens may not be sufficient to treat patients with Marfan syndrome.
Further phenotypic characterization of LEPREL1-related ectopia lentis
Published in Ophthalmic Genetics, 2019
This report highlights the clinical features in a second family presenting with ectopia lentis related to underlying homozygous LEPREL1 mutation. In addition to axial and lenticular myopia, LEPREL1-related ectopia lentis in this proband was associated with smooth irides, a known feature of COL18A1-related ectopia lentis (5). Although this feature was not previously highlighted for LEPREL1-related ectopia lentis, a review of the published clinical images from the previously-reported family confirms a similar finding (4). On the other hand, the severe chorioretinal atrophy noted in these two sisters was not seen in the previously-reported family (4). Smooth irides may be a useful clinical phenotypic feature to help distinguish ectopia lentis related to LEPREL1 mutations from other recognizable genetic causes of ectopia lentis (4).