Phenotypic expansion of Bosch-Boonstra-Schaaf optic atrophy syndrome and further evidence for genotype-phenotype correlations.

Bosch-Boonstra-Schaaf Optic Atrophy Syndrome (BBSOAS) is an autosomal dominant neurodevelopmental disorder caused by loss-of-function variants in NR2F1 and characterized by visual impairment, developmental delay, and intellectual disability. Here we report 18 new cases, provide additional clinical information for 9 previously reported individuals, and review an additional 27 published cases to present a total of 54 patients. Among these are 22 individuals with point mutations or in-frame deletions in the DNA-binding domain (DBD), and 32 individuals with other types of variants including whole-gene deletions, nonsense and frameshift variants, and point mutations outside the DBD. We corroborate previously described clinical characteristics including developmental delay, intellectual disability, autism spectrum disorder diagnoses/features thereof, cognitive/behavioral anomalies, hypotonia, feeding difficulties, abnormal brain MRI findings, and seizures. We also confirm a vision phenotype that includes optic nerve hypoplasia, optic atrophy, and cortical visual impairment. Additionally, we expand the vision phenotype to include alacrima and manifest latent nystagmus (fusional maldevelopment), and we broaden the behavioral phenotypic spectrum to include a love of music, an unusually good long-term memory, sleep difficulties, a high pain tolerance, and touch sensitivity. Furthermore, we provide additional evidence for genotype-phenotype correlations, specifically supporting a more severe phenotype associated with DBD variants.

Threatening drug-drug interaction in a kidney transplant patient with coronavirus disease 2019 (COVID-19).

During the novel coronavirus pandemic, organ transplant recipients represent a frail susceptible category due to long-term immunosuppressive therapy. For this reason, clinical manifestations may differ from general population and different treatment approaches may be needed. We present the case of a 36-year-old kidney-transplanted woman affected by Senior-Loken syndrome diagnosed with COVID-19 pneumonia after a contact with her positive mother. Initial symptoms were fatigue, dry cough, and coryza; she never had fever nor oxygen supplementation. Hydroxychloroquine and lopinavir/ritonavir were started, and the antiviral drug was replaced with darunavir/cobicistat after 2 days for diarrhea. Immunosuppressant levels were closely monitored, and we observed very high tacrolimus trough levels despite initial dose reduction. The patient was left with steroid therapy alone. The peculiarity of clinical presentation and the management difficulties represent the flagship of our case report. We stress the need for guidelines in transplant recipients with COVID-19 infection with particular regard to the management of therapy.

GAPO syndrome with craniosynostosis and intracranial hypertension.

BACKGROUND: GAPO (growth retardation, alopecia, pseudoanodontia, and optic atrophy) as a rare genetic disorder includes growth retardation, alopecia, pseudoanodontia, and optic atrophy. It was reported to be associated with craniosynostosis and intracranial hypertension. CASE REPORT: A patient with such a rare disorder associated with multisuture craniosynostosis and headache is presented. Surgery has been done due to intracranial hypertension. CONCLUSIONS: Abnormal intraoperative findings including sever pericranium and dural adhesions and extraordinary bleeding related to this syndrome are described.

GAPO Syndrome-A Rare Cause of Osteomyelitis of Jaws; Report of 4 Cases With a Brief Review of the Literature.

GAPO syndrome is characterized by growth retardation, alopecia, pseudoanodontia, and ophthalmic abnormalities. This very rarely reported syndrome affects various ethnic groups and can present with manifestations other than those usually reported. Pseudoanodontia is a rare clinical and radiologic manifestation that is always associated with GAPO syndrome. Osteomyelitis of the jaws is a less common disease that is usually attributed to odontogenic causes. This case report describes osteomyelitis of the mandible in a patient with GAPO syndrome. Further, an additional 3 cases of GAPO in the patient's family, with special emphasis on oral mucosal changes and pseudoanodontia, are discussed.

GAPO syndrome: a new syndromic cause of premature ovarian insufficiency.

Premature ovarian insufficiency has the following causes: genetic, autoimmune, metabolic, infectious, and iatrogenic dysfunctions (including radiotherapy, chemotherapy and surgery). However, premature ovarian insufficiency remains without a definite cause in a substantial number of cases. This article describes GAPO syndrome in association with premature ovarian insufficiency, as well as a novel ANTXR1 gene mutation. Histopathological study of the ovaries of a woman with hypergonadotropic hypogonadism revealed extensive deposition of hyaline extracellular material, with bilateral parenchymal atrophy and follicular depletion. Molecular study revealed a novel ANTXR1 gene mutation. The homozygous c.378 + 3A > G transition at the consensus donor splice site of intron 4 was identified. Our results support the involvement of ANTRX1 gene mutations in deregulated extracellular matrix. In addition, our study identified a novel ANTXR1 mutation causing GAPO syndrome, indicating it as a new cause of early loss of ovarian function.

The spectrum of clinical presentation, diagnosis, and management of mitochondrial forms of diabetes.

Primary mitochondrial diseases refer to a group of heterogeneous and complex genetic disorders affecting 1:5000 people. The true prevalence is anticipated to be even higher because of the complexity of achieving a diagnosis in many patients who present with multisystemic complaints ranging from infancy to adulthood. Diabetes is a prominent feature of several of these disorders which might be overlooked by the endocrinologist. We here review mitochondrial disorders and describe the phenotypic and pathogenetic differences between mitochondrial diabetes mellitus (mDM) and other more common forms of diabetes mellitus.

Arterial and venous thrombosis of the cerebral vasculature in GAPO syndrome.

A 37-year-old male, previously diagnosed with GAPO syndrome, was admitted to our hospital complaining of recurrent episodes of transient weakness and numbness in his left arm for 3 months, and severe headache with progressive dysphagia for 15 days. His cranial magnetic resonance (MR) images showed multiple ischemic foci in the bilateral periventricular and supraventricular white matter. Cerebral MR-angiography showed total occlusion of the right internal carotid artery and moderate stenosis in the left internal carotid. We also detected chronic thrombotic changes in the distal left sigmoid sinus, proximal right sigmoid sinus, and bilateral jugular veins on cerebral MR-venography. He was diagnosed with dilated cardiomyopathy at age 31 years, which was reported as a novel association; and later he had a myocardial infarction at age 34 years. To the best of our knowledge, this is the first patient with GAPO syndrome and arterial atherosclerosis in cerebral-as well as coronary-arteries and intracranial venous thrombosis. We report the evolution of the disease in this patient, who died at age 38 years due to respiratory failure secondary to lower respiratory tract infection.

Nonsense mutation in TMEM126A causing autosomal recessive optic atrophy and auditory neuropathy.

PURPOSE: To define the phenotype and elucidate the molecular basis for an autosomal recessively inherited optic atrophy and auditory neuropathy in a consanguineous family with two affected children. METHODS: Family members underwent detailed ophthalmologic, electrophysiological, and audiological assessments. An autozygosity mapping strategy using high-density single nucleotide polymorphism microarrays and microsatellite markers was used to detect regions of genome homozygosity that might contain the disease gene. Candidate genes were then screened for mutations by direct sequencing. RESULTS: Both affected subjects had poor vision from birth and complained of progressive visual loss over time. Current visual acuity ranged from 6/60 to 6/120. Fundus examination revealed bilateral temporal optic nerve pallor in both patients with otherwise normal retinal findings. International-standard full-field electroretinograms were normal in both individuals, with no evidence of generalized retinal dysfunction. Pattern cortical visual evoked potentials were grossly abnormal bilaterally in both cases. The pattern electroretinogram N95:P50 ratio was subnormal, and the P50 was of shortened peak time bilaterally in both patients. The electrophysiological findings were consistent with bilateral retinal ganglion cell/optic nerve dysfunction. Audiological investigation in both siblings revealed abnormalities falling within the auditory neuropathy/dysynchrony spectrum. There were no auditory symptoms and good outer hair cell function (as demonstrated by transient evoked otoacoustic emissions) but impaired inner hair cell/neural function with abnormal stapedial reflex thresholds and abnormal or absent auditory brainstem-evoked responses. The single nucleotide polymorphism microarray data demonstrated a 24.17 Mb region of homozygosity at 11q14.1-11q22.3, which was confirmed by microsatellite marker analysis. The candidate target region contained the transmembrane protein 126A (TMEM126A) gene, and direct sequencing identified a previously described nonsense mutation (c.163C>T; p.Arg55X). CONCLUSIONS: We describe the first detailed phenotyping of patients with autosomal recessive TMEM126A-associated optic atrophy and auditory neuropathy. These findings will facilitate the identification of individuals with this recently described disorder.

Senior-Løken syndrome and intracranial hypertension.

BACKGROUND: Senior-Løken syndrome (SLS) is a rare autosomal recessive disease characterised by nephronophthisis and retinal degeneration, and belongs to a group of genetically heterogeneous disorders known as the ciliopathies. MATERIALS AND METHODS: Case report of a  patient with genetically proven SLS presenting with headaches and swollen optic nerve heads, review of medical notes and ophthalmic imaging, with retinal photography, fundus autofluorescence, and OCT retinal nerve fibre layer analysis. RESULTS: We present findings in a 15 year old girl with Senior-Løken syndrome associated with compound heterozygous mutations in the SDCCAG8 gene,  who initially presented with a retinal dystrophy, and subsequent renal failure requiring renal transplantation and immunosuppression. Four and a half years later, she presented with headaches, reduced vision and clinical findings of papilloedema.  Cerebrospinal fluid analysis revealed a high opening pressure of 37cmH20 and neuroimaging was otherwise unremarkable.  Treatment with a reduced dose of oral acetazolamide resulted in symptomatic relief of headaches, and resolution of optic nerve swelling. CONCLUSION: The association of intracranial hypertension in a ciliopathy is a rare occurrence.  The aetiology of intracranial hypertension in this case is likely multi-factorial, due to renal transplantation, post-renal transplant medications and/ or weight gain.  With evidence of cilia involvement in the central nervous system, ciliary dysfunction may contribute to intracranial hypertension, and should be considered in these patients presenting with headaches. Diagnosis may be difficult with advanced retinal degeneration and baseline retinal nerve fibre layer thinning. Treatment requires careful monitoring of renal function.

Molecular characterization of Leber congenital amaurosis in Koreans.

PURPOSE: Leber congenital amaurosis (LCA) is the most severe form of inherited retinal dystrophy, and invariably leads to blindness. LCA is a genetically and clinically heterogenous disorder. Although more than nine genes have been found to be associated with LCA, they only account for about half of LCA cases. We performed a comprehensive mutational analysis on nine known genes in 20 unrelated patients to investigate the genetic cause of LCA in Koreans. METHODS: All exons and flanking regions of the nine genes (AIPL1, CRB1, CRX, GUCY2D, RDH12, RPE65, RPGRIP1, LRAT, and TULP1) were analyzed by direct sequencing. We also screened our patients for the common CEP290: c.2991+1655A>G mutation found in Caucasian. RESULTS: Six different mutations including four novel ones were identified in three patients (15.0%): one frameshift, one nonsense, one splicing, and three missense mutations. These patients were compound heterozygotes and harbored two different mutations in CRB1, RPE65, and RPGRIP1, respectively. We identified three novel unclassified missense variants in RPGRIP1 of the three patients. These patients were heterozygous for each variant and did not have a large deletion or duplication in the same gene. CONCLUSIONS: This comprehensive mutational analysis shows marked genetic heterogeneity in Korean LCA patients and reveals a mutation spectrum that differs from those previously reported. In turn, this suggests that a different strategy should be used for the molecular diagnosis of LCA in Koreans.

Molecular Study of Nephronophthisis in 7 Unrelated Pakistani Families.

Nephronophthisis is an autosomal recessive cystic kidney disease characterized by tubular interstitial infiltration, periglomerular fibrosis, and cysts, and is the most frequent genetic cause of end-stage renal disease in children. Nephronophthisis is pleiotropic as almost all the causative genes are involved in primary cilium and centrosome function which are found in almost all human cells. Genetic heterogeneity in nephronophthisis makes the molecular and genetic diagnosis somewhat difficult. Homozygous deletions in the nephronophthisis 1 (NPHP1) gene are the major contributor of nephronophthisis cases, while other genes accounts for less than 3% each. Nephronophthisis-related ciliopathy is a term used for extrarenal symptoms in addition to nephronophthisis. Herein, we are reporting the molecular study of 7 children from independent families fulfilling the criteria of nephronophthisis. A deletion analysis of the NPHP1 gene was performed in each case, and NPHP5 mutation screening was performed in the absence of such deletion in patients with Senior Loken syndrome.

[An OPA3 gene mutation is responsible for the disease associating optic atrophy and cataract with extrapyramidal signs]. / Atrophie optique, cataracte et signes extra-pyramidaux par mutation du gène OPA3.

INTRODUCTION: In 1961, Garcin et al. described a family with several members affected with optic atrophy associated with cataract, and neurological symptoms. The authors believed this condition to be distinct from other diseases known at that time, e.g. the Behr syndrome, Marinesco-Sjogren syndrome and Friedreich's ataxia. METHOD: This family was followed over a period of 40 years and genes known to be responsible for optic atrophy were sequenced. RESULTS: The G277A mutation of OPA3 gene was responsible for this familial disease. DISCUSSION: A new clinical entity is identified: autosomal dominant optic atrophy and cataract, due to a heterozygous mutation of the OPA3 gene, a nuclear gene encoding a mitochondrial protein.

Atypical Leber's hereditary optic neuropathy with molecular confirmation.

OBJECTIVE: Leber's hereditary optic neuropathy (LHON) is typically a familial disease of primarily young, male adults. Analysis of mitochondrial DNA has identified point mutations associated with LHON and allowed us to identify cases of LHON not consistent with traditional descriptions of the disease. DATA SOURCES: The collective experience of three tertiary referral centers contributed to this report. STUDY SELECTION: Patients with bilateral optic neuropathies who were positive for the 11778 LHON mutation were included in this study if they were female and there was no family history of visual loss. DATA EXTRACTION: Six case histories are presented. DATA SYNTHESIS: The diagnosis of LHON remained unknown in six female patients with bilateral optic neuropathies until molecular analysis revealed the 11778 mitochondrial DNA mutation. None of the patients had a family history of visual loss, and five were initially diagnosed as having factitious visual loss. Other individual features atypical for LHON included lack of the characteristic LHON funduscopic appearance, bitemporal hemianopia, optic disc cupping, and premonitory episodes of transient visual loss. In one patient the correct diagnosis was delayed 17 years. CONCLUSIONS: The diagnosis of LHON should be considered in all cases of unexplained optic neuropathy, including those with negative family history, late or early age at onset, female gender, or normal funduscopic appearance.

mtDNA analysis of Leber hereditary optic neuropathy associated with spondyloepiphyseal dysplasia.

A patient was diagnosed in 1974 with the unique combination of Leber hereditary optic neuropathy (LHON) and spondyloepiphyseal dysplasia. The entire mitochondrial DNA (mtDNA) sequence from this patient was determined in order to identify candidate pathogenic mutations. The patient's mtDNA carried the LHON mutation at nucleotide 14484, thus elucidating the etiology of his optic neuropathy. We also identified another ND6 mutation at nucleotide 14420. This latter mutation is probably a clinically benign private polymorphism, although a pathogenic role in his skeletal abnormalities or in his optic neuropathy cannot yet be ruled out.

Joubert syndrome associated with Leber amaurosis and multicystic kidneys.

We describe a boy with manifestations of Joubert syndrome, Leber congenital amaurosis, and multicystic kidneys. In infants with unexplained neonatal tachypnea and late developmental delay, absence or hypoplasia of the cerebellar vermis should be sought. Joubert syndrome probably is an autosomal recessive disorder. In the subsequent pregnancy of the propositus' mother, we were able to make a prenatal diagnosis of Joubert syndrome, one of the first to be reported.

Cerebellar ataxia in patients with Leber's hereditary optic neuropathy.

We report the cases of a mother and son with Leber's hereditary optic neuropathy (LHON), where a point mutation of mitochondria DNA from guanine to adenine on nucleotide position 11778 was verified. Both also had cerebellar ataxia and dysarthria and in both cases cerebellar atrophies were detected by computed tomography or magnetic resonance imaging. It was not possible to elucidate the relationship between LHON and the cerebellar atrophy, but it should be kept in mind that various neurological complications may occur in LHON.

Mitochondrial mutations of Leber's hereditary optic neuropathy: a risk factor for multiple sclerosis.

Multiple sclerosis (MS) and Leber's hereditary optic neuropathy (LHON) have been found to occur in combination. Based on an extensive literature search and on a clinical analysis of 55 LHON pedigrees (103 patients) and 40 patients with definite MS, this study concludes that the association of LHON and MS is more than a coincidence, and that carrying a primary LHON mutation is a risk factor for developing MS. All three primary LHON mutations occurring in the European and North American populations have been found to be associated with an MS-like syndrome. The neurological characteristics of MS associated with LHON are indistinguishable from those of MS in general, but the severe and bilateral visual symptoms and signs justify considering these patients as a clinical subgroup of MS and screening them for LHON mutations. However, screening LHON patients for MS appears to be more rewarding.