Current phenotypic and genetic spectrum of syndromic deafness in Tunisia: paving the way for precision auditory health.

Hearing impairment (HI) is a prevalent neurosensory condition globally, impacting 5% of the population, with over 50% of congenital cases attributed to genetic etiologies. In Tunisia, HI underdiagnosis prevails, primarily due to limited access to comprehensive clinical tools, particularly for syndromic deafness (SD), characterized by clinical and genetic heterogeneity. This study aimed to uncover the SD spectrum through a 14-year investigation of a Tunisian cohort encompassing over 700 patients from four referral centers (2007-2021). Employing Sanger sequencing, Targeted Panel Gene Sequencing, and Whole Exome Sequencing, genetic analysis in 30 SD patients identified diagnoses such as Usher syndrome, Waardenburg syndrome, cranio-facial-hand-deafness syndrome, and H syndrome. This latter is a rare genodermatosis characterized by HI, hyperpigmentation, hypertrichosis, and systemic manifestations. A meta-analysis integrating our findings with existing data revealed that nearly 50% of Tunisian SD cases corresponded to rare inherited metabolic disorders. Distinguishing between non-syndromic and syndromic HI poses a challenge, where the age of onset and progression of features significantly impact accurate diagnoses. Despite advancements in local genetic characterization capabilities, certain ultra-rare forms of SD remain underdiagnosed. This research contributes critical insights to inform molecular diagnosis approaches for SD in Tunisia and the broader North-African region, thereby facilitating informed decision-making in clinical practice.

Genetic testing for hereditary cancer syndromes in Tunisian patients: Impact on health system.

INTRODUCTION: Cancer management in Africa faces diverse challenges due to limited resources, health system challenges, and other matters. Identifying hereditary cancer syndromic cases is crucial to improve clinical management and preventive care in these settings. This study aims to explore the clinicopathological features and genetic factors associated with hereditary cancer in Tunisia, a North African country with a rising cancer burden MATERIALS AND METHODS: Clinicopathological features and personal/family history of cancer were explored in 521 patients. Genetic analysis using Sanger and next-generation sequencing was performed for a set of patients RESULTS: Hereditary breast and ovarian cancer syndrome was the most frequent cluster in which 36 BRCA mutations were identified. We described a subgroup of patients with likely ''breast cancer-only syndrome'' among this cluster. Two cases of Li-Fraumeni syndrome with distinct TP53 mutations namely c.638G>A and c.733G>A have been identified. Genetic investigation also allowed the identification of a new BLM homozygous mutation (c.3254dupT) in one patient with multiple primary cancers. Phenotype-genotype correlation suggests the diagnosis of Bloom syndrome. A recurrent MUTYH mutation (c.1143_1144dup) was identified in three patients with different phenotypes CONCLUSION: Our study calls for comprehensive genetic education and the implementation of genetic screening in Tunisia and other African countries health systems, to reduce the burden of hereditary diseases and improve cancer outcomes in resource-stratified settings.

Comorbidity of bathing suit ichthyosis and limb-girdle muscular dystrophy type 2 A in a Tunisian patient revealed by Whole Exome Sequencing.

Elevated rates of consanguinity and inbreeding are responsible for the high prevalence of recessively inherited diseases among inbred populations including Tunisia. In addition, the co-occurrence of two of these conditions, called also comorbidity, within the same individual or in members of the same family are often described in Tunisia which is challenging for diagnosis. The high throughput sequencing has improved the diagnosis of inherited diseases. We report here on a 32-year-old woman born to consanguineous parents. She presented with congenital ichthyosis and muscular dystrophy. She was primarily suspected as suffering from Chanarin-Dorfman syndrome (CDS) with unusual form. Screening of founder mutations allowed only the elucidation of the molecular etiology of Ichthyosis. As the result was inconclusive, Whole Exome Sequencing (WES) was conducted. WES data analysis led to the identification of a mutation in the CAPN3 gene underlying limb-girdle muscular dystrophy type 2A (LGMD2A). Sanger sequencing confirmed the familial segregation of mutations. This work presents the first case worldwide of individual comorbidity of bathing suit ichthyosis and LGMD2A. The co-occurrence of two diseases should be systematically considered when establishing a diagnosis especially in consanguineous populations. WES is a powerful tool for molecular diagnosis in particular for revealing comorbidities and rectifying the diagnosis.

Review of Piezoelectric Properties and Power Output of PVDF and Copolymer-Based Piezoelectric Nanogenerators.

The highest energy conversion efficiencies are typically shown by lead-containing piezoelectric materials, but the harmful environmental impacts of lead and its toxicity limit future use. At the bulk scale, lead-based piezoelectric materials have significantly higher piezoelectric properties when compared to lead-free piezoelectric materials. However, at the nanoscale, the piezoelectric properties of lead-free piezoelectric material can be significantly larger than the bulk scale. The piezoelectric properties of Poly(vinylidene fluoride) (PVDF) and Poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) lead-free piezoelectric nanomaterials are reviewed and their suitability for use in piezoelectric nanogenerators (PENGs) is determined. The impact of different PVDF/PVDF-TrFE composite structures on power output is explained. Strategies to improve the power output are given. Overall, this review finds that PVDF/PVDF-TrFE can have significantly increased piezoelectric properties at the nanoscale. However, these values are still lower than lead-free ceramics at the nanoscale. If the sole goal in developing a lead-free PENG is to maximize output power, lead-free ceramics at the nanoscale should be considered. However, lead-free ceramics are brittle, and thus encapsulation of lead-free ceramics in PVDF is a way to increase the flexibility of these PENGs. PVDF/PVDF-TrFE offers the advantage of being nontoxic and biocompatible, which is useful for many applications.

Constitutional mismatch repair deficiency syndrome with atypical features caused by a homozygous MLH1 missense variant (c.1918C>A, p.(Pro640Thr)): a case report.

Constitutional mismatch repair deficiency (CMMRD) syndrome is a rare autosomal recessive genetic disorder caused by biallelic germline mutations in one of the mismatch repair genes. Carriers are at exceptionally high risk for developing, typically in early life, hematological and brain malignancies, as well as cancers observed in Lynch syndrome. We report a homozygous MLH1 missense variant (c.1918C>A p.(Pro640Thr)) in a Tunisian patient with CMMRD syndrome and a family history of early-age colorectal cancer. The proband presented initially with colonic oligopolyposis and adenosquamous carcinoma of the caecum. He later developed several malignancies, including undifferentiated carcinoma of the parotid, grade 4 IDH-mutant astrocytoma, and ampulla of Vater adenocarcinoma. The patient was older than typical for this disease and had a remarkably prolonged survival despite developing four distinct aggressive malignancies. The current report highlights the challenges in assessing the pathogenicity of the identified variant and the remarkable phenotypic diversity in CMMRD.

Primary Hyperoxaluria Type 1: Clinical, Paraclinical, and Evolutionary Aspects in Adults from One Nephrology Center.

Introduction: Primary hyperoxaluria type 1 (PH1) is a rare and inherited condition of urolithiasis. The aim of our study was to analyze clinical, paraclinical, and evolutionary aspects of PH1 in adult patients in our Nephrology department. Methods: We conducted a retrospective single-center study between 1990 and 2021. We collected patients followed for PH1 confirmed by genetic study and/or histopathological features of renal biopsy and morphoconstitutional analysis of the calculi. Results: There were 25 patients with a gender ratio of 1.78. The median age at onset of symptoms was 18 years. A delay in diagnosis more than 10 years was noted in 13 cases. The genetic study found the I244T mutation in 17 cases and 33-34 InsC in 4 cases. A kidney biopsy was performed in 5 cases, on a native kidney in 4 cases and on a graft biopsy in one case. The analysis of calculi was done in 10 cases showing type Ic in 2 cases. After a median follow-up of 13 years (1 year-42 years), 14 patients progressed to end-stage chronic renal failure (ESRD). The univariate study demonstrated a remarkable association with progression to ESRD in our population (44% vs. 56%) RR = 13.32 (adjusted ORs (95% CI): 2.82-62.79) (p < 0.01). Conclusion: Progression to ESRD was frequent in our series. Early diagnosis and adequate management can delay such an evolution.

Pathologic complete response to neoadjuvant imatinib of a gastric stromal tumor with concomitant mutations in KIT: A case report and literature review.

Key clinical message: We report the first case of pathologic complete response (pCR) to neoadjuvant imatinib in a gastric stromal tumor harboring KIT mutations in both exons 11 and 9. The significance of this co-occurrence is unknown and might increase the responsiveness of gastrointestinal stromal tumors (GISTs) to imatinib. Abstract: pCR of GIST to neoadjuvant imatinib is rare. We report a case of pCR to neoadjuvant imatinib in a gastric stromal tumor that harbored co-occurrence of multiple KIT mutations in exons 11 and 9. This co-occurrence in exons 9 and 11 is the first to be reported in the English literature.

Turner syndrome: results of the first Tunisian study group on Turner syndrome (TuSGOT).

OBJECTIVES: Early diagnosis in Turner syndrome is desirable to optimize growth and puberty and yet, it is often made late. Here, we aim to identify age at diagnosis, clinical features at presentation and potential strategies to improve the care of TS girls. METHODS: Retrospective study, including patients from 14 care centers across Tunisia including neonatal and pediatric care units, adult endocrinology and genetics departments. RESULTS: We identified 175 patients with TS, karyotype showing 45, xmonosomy in 83(47.4 %) with mosaicism in 37(20 %). Mean ± SD, median (range) age at diagnosis available in 173 patients was 13 ± 9.2,12 (birth-48) years. The diagnosis was antenatal in 4(2.3 %), from birth-2 years in 14 (8 %)with lymphoedema (8)and dysmorphic features (9),2-12 years in 53 (35.5 %) including 35 with short stature, 13-18 years in 43(28.8 %) with short stature(28) and delayed puberty(14) and 35(23.5 %) after 18 years, related to ovarian insufficiency (20) and short stature (11). The associated malformations were cardiac in 14 (12.8 %), renal in 22 (19.6 %). A total of 56 girls (32 %) had proven gonadal dysgenesis and 13 (7 %) had otological problems. Parental height was available in 71 girls (40 %) of whom 59 were below the lower end of parental target range (LTR) (83 %). CONCLUSIONS: This first Tunisian multicenter study, the first African of its kind, reveals that more than half of Turner syndrome cases are diagnosed after the age of 12 years. Subsequently, national strategies for an earlier TS diagnosis are needed such as measuring and plotting parental heights as well as introducing a systematic height screening at 5 years in Tunisia with a view to carrying out a re-audit in five years' time.

Review of Zinc Oxide Piezoelectric Nanogenerators: Piezoelectric Properties, Composite Structures and Power Output.

Lead-containing piezoelectric materials typically show the highest energy conversion efficiencies, but due to their toxicity they will be limited in future applications. In their bulk form, the piezoelectric properties of lead-free piezoelectric materials are significantly lower than lead-containing materials. However, the piezoelectric properties of lead-free piezoelectric materials at the nano scale can be significantly larger than the bulk scale. This review looks at the suitability of ZnO nanostructures as candidate lead-free piezoelectric materials for use in piezoelectric nanogenerators (PENGs) based on their piezoelectric properties. Of the papers reviewed, Neodymium-doped ZnO nanorods (NRs) have a comparable piezoelectric strain constant to bulk lead-based piezoelectric materials and hence are good candidates for PENGs. Piezoelectric energy harvesters typically have low power outputs and an improvement in their power density is needed. This review systematically reviews the different composite structures of ZnO PENGs to determine the effect of composite structure on power output. State-of-the-art techniques to increase the power output of PENGs are presented. Of the PENGs reviewed, the highest power output belonged to a vertically aligned ZnO nanowire (NWs) PENG (1-3 nanowire composite) with a power output of 45.87 µW/cm2 under finger tapping. Future directions of research and challenges are discussed.

Genotype-Phenotype correlation of distal renal tubular acidosis in Tunisia.

INTRODUCTION: Distal renal tubular acidosis (dRTA) is a rare genetic disorder due to the incapacity of the α intercalated cells to excrete protons in the collecting duct. This impaired distal acidification of urine leads to a chronic hyperchloremic metabolic acidosis with a normal plasma anion gap, hypokalemia, and hypercalciuria with hypocitraturia causing nephrocalcinosis. Primary dRTA is inherited either as an autosomal dominant (SLC1A4 gene) or autosomal recessive trait (ATP6V0A1/ATP6V1B1 genes). AIM: To analyze the genotype-phenotype correlation of dTA in Tunisia. METHODS: In this study we present all available data of patients followed in our center for dRTA over the last 28 years and who had a genetic study. This was a retrospective descriptive study from January 1991 to December 2018, conducted in the Pediatrics Department of the Charles Nicolle Hospital in Tunis. RESULTS: Twenty-five cases of dRTA were collected and were offered genetic analysis to confirm the diagnosis. The molecular mutation was confirmed in 13 patients of whom 11 had homozygous mutations in ATP6V1B1(G1) and 2 had homozygous mutations in ATP6V0A4(G2). Median age of diagnosis was 8.9 months. Severe growth retardation was documented in nine children with mutations in ATP6V1B1, in eight children with no genetic mutation and in the two patients with a mutation in ATP6V0A4. All children were found to have metabolic acidosis at initial presentation. Hypokalemia was found in 19 children. All patients were polyuric. Twenty-two patients had nephrocalcinosis (88%). The treatment was based on alkali prescription and substitution of potassium chloride. Sensorineural hearing loss (SNHL) was documented in 12 children. At the last consultation, 14 patients had chronic kidney disease (CKD) stage 2 or higher, 8 of whom were in the group with negative genetic analysis. CONCLUSION: According to the early onset in patients, the recessive mode seems to be the mode of transmission in Tunisia. dRTA was long considered to not affect renal function, but we note a decline in eDFG.

Primary hyperoxaluria type 1: Clinical, genetic, and evolutionary characteristics in Tunisian children.

INTRODUCTION: There are three types of primary hyperoxaluria, with type 1 considered the most severe. AIM: To analyze the clinical, genetic, and evolutionary characteristics of type 1 primary hyperoxaluria with pediatric onset. METHODS: This was a retrospective, descriptive study that included Tunisian children under the age of 18 at the time of diagnosis over a period of 25 years (January 1, 1996, to December 31, 2022). RESULTS: Thirty-five patients were included, with a mean age of 4.1 years. The most common presenting circumstances of the disease were nephrolithiasis and end-stage renal failure. The average serum creatinine level was 225.42 µmol/l. Five mutations were identified, with the p.Ile244Thr mutation being the most prevalent. Nephrocalcinosis, surgical intervention, and a creatinine level ≥57 µmol/l were predictive of progression to end-stage renal failure. The infantile form was predictive of mortality. CONCLUSIONS: Screening for the disease would improve the prognosis of this condition.

Phenotype Spectrum in Tunisian Population with NPHP1 Deletion.

Introduction: Nephronophthisis (NPHP) is a tubulointerstitial kidney disorder with an autosomal recessive inheritance pattern. Its genetic heterogeneity contributes to phenotype variability. The most frequent etiology of juvenile nephronophthisis is a mutation in the nephronophthisis type 1 (NPHP1) gene. This study aimed to evaluate the genotype-phenotype correlation in NPHP1 gene mutation. Methods: A multicenter retrospective study was performed over 20 years from 1998 to 2018 to describe the clinical, biological, and radiological features associated with the large deletion NPHP1 gene in 32 patients. Results: The incidence of NPHP1 was 1.6/204041. Eighty-one percent of our patients were born out of consanguineous marriages. The mean age at diagnosis was 14 ± 7 years. The patients were divided into three groups: isolated nephronophthisis (72%), syndromic nephronophthisis (19%), and patients without recognizable syndrome (9%). Intrafamilial and geographical variability was observed in syndrome diagnoses and in age at the onset of CKD stage 5. Genotype frequency varied between 50% and 100% in genealogical data. Juvenile (47%), adolescent (37%), and adult (13%) clinical forms have been distinguished by the onset of CKD stage 5. The five-year survival rate of renal transplantation was 80%. Conclusion: Given the broad clinical spectrum of NPHP1 associated with the large deletion of the NPHP1 gene, no genotype-phenotype correlation could be established.

[Epidemiological, clinical and evolutionary particularities of primary distal tubular acidosis in Tunisian children]. / Particularités épidémiologiques, cliniques et évolutives de l'acidose tubulaire distale primitive chez l'enfant tunisien.

INTRODUCTION: The distal renal tubular acidosis of children is characterized by hyperchloremic metabolic acidosis with normal anion gap, hypokalemia, hypercalciuria and nephrocalcinosis. It is secondary to the inability of alpha intercalar cells of the distal tubule to acidify urine of genetic origin. OBJECTIVE: To analyse the epidemiological aspects of distal tubular acidosis in Tunisia and study its evolutionary profile. PATIENTS AND METHODS: We conducted a retrospective descriptive study involving 44 patients followed at the paediatrics department of the Charles Nicolle Hospital in Tunis for 28 years (1991-2018). RESULTS: The most common discovery circumstances were growth retardation (88.6%), dehydration (56.8%), ployuro-polydipsic syndrome (47.7%), vomiting (40.9%) and nephrocalcinosis (38.6%). Growth retardation was found in 52.3% of patients. Dehydration was diagnosed in 59.1% of patients on the first exam. Polyuria was constant with an average diuresis of 8 cc/kg/h. All patients had the complete form of distal renal tubular acidosis with an average alkaline reserve of 11.1 mmol/L. Nephocalcinosis was found in 77.3% associated with nepholithiasis in 22.7%. Twenty-four patients had sensorineural deafness, nine of whom had ATP6V1B1/2p13 mutation. The ATP6V0A4/7q33-34 mutation was present in two patients. We used a high alkaline treatment dose with an average maintenance dose of 8.17 mmol/kg/24 hours. In the long term, stunting persisted in 34% of patients. The mean of creatinine's clearance at the last evaluation was 89.38 mL/min/1.73 m2 SC with stage 2 of chronic kidney disease in 50% of patients. CONCLUSION: Distal renal tubular acidosis has long been considered a benign pathology but is responsible for a progressive decline in GFD. Adequate metabolic control is needed to stabilize kidney function.

3M syndrome: A Tunisian seven-cases series.

3M syndrome (3MS) is a rare autosomal recessive primordial growth disorder characterized by a severe pre- and post-natal growth deficiency, minor dysmorphisms and skeletal abnormalities, contrasting with normal intellect and endocrine function. Three different genes have been so far involved in the disease, with mutations in CUL7, OBSL1 and CCDC8. The CUL7 gene mutations are accountable for 77,5% of the genetically confirmed patients, with a founder mutation identified in exon 24 for the Maghreb families. The follow up is mainly orthopedic with possible GH-based treatment. The objective of this report was to carry out a clinical analysis of a series of Tunisian patients with features evoking 3MS and to perform a molecular analysis of the CLU7 exon 24. We carried out a descriptive retrospective study including Tunisian patients who consulted at the congenital disorders and hereditary diseases department of Charles Nicolle's hospital, Tunis, Tunisia, for intra-uterine onset growth retardation with normal intellect. We selected the patients having characteristic 3MS facial dysmorphia. The molecular analysis of the CUL7 exon 24 was performed using PCR and Sanger sequencing searching the founder mutation c.4451_4452delTG. Seven patients were included in this study. Consanguinity was noted for four families. The mean age at the first consult was 2.5 years. All the patients had an intra-uterine onset growth retardation with a preserved head circumference. All patients presented facial dysmorphia of 3MS, with a prominent forehead (7/7), a triangular face (6/7), an underdeveloped midface (7/7), a fleshy tipped nose (5/7), anteverted nares (6/7), a long philtrum (7/7) and full lips (4/7). All the patients presented skeletal abnormalities with various severities such as lumbar lordosis, hyperextensible joints, short thorax, square shoulders, hip dislocation, and prominent heels. Less frequent features were noted such as spina bifida occulta in one case, and single transverse palmar crease in 4 cases. One GH treatment response was reported. The molecular genetic analysis of the CUL7 gene (exon 24) revealed the founder mutation for all the patients which reinforces the hypothesis of founder effect for 3MS in the Tunisian population.

Spectrum of Genetic Diseases in Tunisia: Current Situation and Main Milestones Achieved.

Genetic diseases in Tunisia are a real public health problem given their chronicity and the lack of knowledge concerning their prevalence and etiology, and the high rates of consanguinity. Hence, we performed systematic reviews of the literature in order to provide a more recent spectrum of these disorders and to expose the challenges that still exist to tackle these kinds of diseases. A manual textual data mining was conducted using MeSH and PubMed databases. Collected data were classified according to the CIM-10 classification and the transmission mode. The spectrum of these diseases is estimated to be 589 entities. This suggests remarkable progress through the development of biomedical health research activities and building capacities. Sixty percent of the reported disorders are autosomal recessive, which could be explained by the high prevalence of endogamous mating. Congenital malformations (29.54%) are the major disease group, followed by metabolic diseases (22%). Sixty percent of the genetic diseases have a known molecular etiology. We also reported additional cases of comorbidity that seem to be a common phenomenon in our population. We also noticed that epidemiological data are scarce. Newborn and carrier screening was only limited to pilot projects for a few genetic diseases. Collected data are being integrated into a database under construction that will be a valuable decision-making tool. This study provides the current situation of genetic diseases in Tunisia and highlights their particularities. Early detection of the disease is important to initiate critical intervention and to reduce morbidity and mortality.

Alpha-mannosidosis in Tunisian consanguineous families: Potential involvement of variants in GHR and SLC19A3 genes in the variable expressivity of cognitive impairment.

Alpha-Mannosidosis (AM) is an ultra-rare storage disorder caused by a deficiency of lysosomal alpha-mannosidase encoded by the MAN2B1 gene. Clinical presentation of AM includes mental retardation, recurrent infections, hearing loss, dysmorphic features, and motor dysfunctions. AM has never been reported in Tunisia. We report here the clinical and genetic study of six patients from two Tunisian families with AM. The AM diagnosis was confirmed by an enzymatic activity assay. Genetic investigation was conducted by Sanger sequencing of the mutational hotspots for the first family and by ES analysis for the second one. In the first family, a frameshift duplication p.(Ser802GlnfsTer129) was identified in the MAN2B1 gene. For the second family, ES analysis led to the identification of a missense mutation p.(Arg229Trp) in the MAN2B1 gene in four affected family members. The p.(Ser802GlnfsTer129) mutation induces a premature termination codon which may trigger RNA degradation by the NMD system. The decrease in the levels of MAN2B1 synthesis could explain the severe phenotype observed in the index case. According to the literature, the p.(Arg229Trp) missense variant does not have an impact on MAN2B1 maturation and transportation, which correlates with a moderate clinical sub-type. To explain the intra-familial variability of cognitive impairment, exome analysis allowed the identification of two likely pathogenic variants in GHR and SLC19A3 genes potentially associated to cognitive decline. The present study raises awareness about underdiagnosis of AM in the region that deprives patients from accessing adequate care. Indeed, early diagnosis is critical in order to prevent disease progression and to propose enzyme replacement therapy.

Identification of Eleven Novel BRCA Mutations in Tunisia: Impact on the Clinical Management of BRCA Related Cancers.

BACKGROUND: Breast cancer is the world's most common cancer among women. It is becoming an increasingly urgent problem in low- and middle-income countries (LMICs) where a large fraction of women is diagnosed with advanced-stage disease and have no access to treatment or basic palliative care. About 5-10% of all breast cancers can be attributed to hereditary genetic components and up to 25% of familial cases are due to mutations in BRCA1/2 genes. Since their discovery in 1994 and 1995, as few as 18 mutations have been identified in BRCA genes in the Tunisian population. The aim of this study is to identify additional BRCA mutations, to estimate their contribution to the hereditary breast and ovarian cancers in Tunisia and to investigate the clinicopathological signatures associated with BRCA mutations. METHODS: A total of 354 patients diagnosed with breast and ovarian cancers, including 5 male breast cancer cases, have been investigated for BRCA1/2 mutations using traditional and/or next generation sequencing technologies. Clinicopathological signatures associated with BRCA mutations have also been investigated. RESULTS: In the current study, 16 distinct mutations were detected: 10 in BRCA1 and 6 in BRCA2, of which 11 are described for the first time in Tunisia including 3 variations that have not been reported previously in public databases namely BRCA1_c.915T>A; BRCA2_c.-227-?_7805+? and BRCA2_c.249delG. Early age at onset, family history of ovarian cancer and high tumor grade were significantly associated with BRCA status. BRCA1 carriers were more likely to be triple negative breast cancer compared to BRCA2 carriers. A relatively high frequency of contralateral breast cancer and ovarian cancer occurrence was observed among BRCA carriers and was more frequent in patients carrying BRCA1 mutations. CONCLUSION: Our study provides new insights into breast and ovarian cancer genetic landscape in the under-represented North African populations. The prevalence assessment of novel and recurrent BRCA1/2 pathogenic mutations will enhance the use of personalized treatment and precise screening strategies by both affected and unaffected North African cancer cases.

Analysis of Optical Diffraction Profiles Created by Phase-Modulating MEMS Micromirror Arrays.

This paper presents modeling and analysis of light diffraction and light-intensity modulation performed by an optical phased array (OPA) system based on metal-coated silicon micromirrors. The models can be used in the design process of a microelectromechanical system (MEMS)-based OPA device to predict its optical performance in terms of its field of view, response, angular resolution, and long-range transmission. Numerical results are derived using an extended model for the 1st-order diffracted light intensity modulation due to phase shift. The estimations of the optical characteristics are utilized in the designs of an OPA system capable of active phase modulation and an OPA system capable of array pitch tuning. Both designs are realized using the Multi-User MEMS Processes (PolyMUMPs) in which polysilicon is used as structural material for the MEMS-actuated mirrors. The experiments are performed to evaluate the optical performance of the prototypes. The tests show that the individually actuated micromirrors, which act as phase shifters, can transmit the most optical power along the 1st-order diffracted beam by actively changing their out-of-plane positions. In addition, the 1st-order diffracted beam with high optical intensity can be steered for distance measurement.