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1.
Science ; 384(6695): 584-590, 2024 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-38696583

RESUMEN

Meningomyelocele is one of the most severe forms of neural tube defects (NTDs) and the most frequent structural birth defect of the central nervous system. We assembled the Spina Bifida Sequencing Consortium to identify causes. Exome and genome sequencing of 715 parent-offspring trios identified six patients with chromosomal 22q11.2 deletions, suggesting a 23-fold increased risk compared with the general population. Furthermore, analysis of a separate 22q11.2 deletion cohort suggested a 12- to 15-fold increased NTD risk of meningomyelocele. The loss of Crkl, one of several neural tube-expressed genes within the minimal deletion interval, was sufficient to replicate NTDs in mice, where both penetrance and expressivity were exacerbated by maternal folate deficiency. Thus, the common 22q11.2 deletion confers substantial meningomyelocele risk, which is partially alleviated by folate supplementation.


Asunto(s)
Deleción Cromosómica , Cromosomas Humanos Par 22 , Meningomielocele , Animales , Femenino , Humanos , Masculino , Ratones , Cromosomas Humanos Par 22/genética , Síndrome de DiGeorge/genética , Secuenciación del Exoma , Ácido Fólico/administración & dosificación , Deficiencia de Ácido Fólico/complicaciones , Deficiencia de Ácido Fólico/genética , Meningomielocele/epidemiología , Meningomielocele/genética , Penetrancia , Disrafia Espinal/genética , Riesgo , Proteínas Adaptadoras Transductoras de Señales/genética
2.
Pak J Med Sci ; 39(6): 1673-1679, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37936764

RESUMEN

Objective: Congenital anomalies (CA) or birth defects cause substantial healthcare burden in developing countries. There are few studies from Pakistan on the prevalence-pattern of CA. The purpose of this study was to determine the prevalence-pattern and genetic attributes of CA at a tertiary care facility in Rawalpindi, Pakistan. Methods: In a cross-sectional study design, patients with CA were ascertained from Pediatric and Neonatal Section of Holy Family Hospital, Rawalpindi from March-2022 to June-2022. International Classification of Diseases (ICD-10) and Online Mendelian Inheritance in Man (OMIM) databases were utilized for uniformity in classification. The pattern of CA as well as familial/sporadic nature, syndromic/isolated presentations, and prenatal consanguinity were estimated. Descriptive summaries were generated. Results: A total of 517 independent cases with certain types of CA were recruited. There were eight major and 70 minor categories. Among the major categories, neurological disorders (39.1%) were predominating followed by neuromuscular disorders (21.1%), limb defects (13.5%), musculoskeletal defects (7.4%), blood disorders (4.3%), orofacial defects (3.9%), metabolic disorders (3.7%), and Others (7.1%). The sporadic cases were in majority (72.5%) compared to familial cases (27.5%). Further, 63% patients had syndromic presentations and there were 37% cases with isolated appearances. A total of 70% cases had parental consanguinity. Conclusion: The majority of anomalies were of preventable nature and certain healthcare measures including antinatal care and counseling can be adopted to minimize their burden. Additionally, there is an urgent need to raise awareness of the negative consequences of consanguineous marriages, which constitute a significant risk factor in cases with inherited CA.

3.
Yale J Biol Med ; 96(3): 367-382, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37780995

RESUMEN

We present a Pakistani kinship afflicted with a syndrome with features including short stature, reduced sitting height, orofacial symptoms including prominent forehead and thick eyebrows, short and broad thorax, and variable features such as long philtrum, short broad neck, barrel chest, thoracic kyphoscoliosis, hypogonadism, and hypospadias. Phenotypic variation even within different sibships was considerable. The unique combination of the phenotypic characteristics prompted us to determine the shared homozygosity regions in patient genomes and the pathogenic variants by next generation technologies like single nucleotide polymorphism (SNP) genotyping and whole exome sequencing (WES). Through these analyses, we detected homozygous OBSL1 c.848delG (p.Gly283AlafsTer54) as the causal variant. Biallelic variants in OBSL1 are known to cause Three M Syndrome 2 (3M2), a rare disorder of growth retardation with characteristic facial dysmorphism and musculoskeletal abnormalities. Affected members of the family do not have the 3M2 hallmark features of dolichocephaly, hypoplastic midface, anteverted nares, low nasal bridge, pectus excavatum, sacral hyperlordosis, spina bifida occulta, anterior wedging of thoracic vertebrae, prominent heels, and prominent talus. Moreover, they have some variable features not typical for the syndrome such as round face, disproportionate short stature, barrel chest, thoracic kyphoscoliosis, hypogonadism, and hypospadias. Our study facilitated genetic diagnosis in the family, expanded the clinical phenotype for 3M2, and unraveled the considerable clinical variation within the same kinship. We conclude that unbiased molecular analyses such as WES should be more integrated into healthcare, particularly in populations with high parental consanguinity, given the potential of such analyses to facilitate diagnosis.


Asunto(s)
Hipogonadismo , Hipospadias , Masculino , Humanos , Mutación/genética , Fenotipo , Hipogonadismo/genética , Proteínas del Citoesqueleto/genética
4.
Yale J Biol Med ; 96(3): 313-325, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37780997

RESUMEN

Laron syndrome (LS) is a rare autosomal recessively segregating disorder of severe short stature. The condition is characterized by short limbs, delayed puberty, hypoglycemia in infancy, and obesity. Mutations in growth hormone receptor (GHR) have been implicated in LS; hence, it is also known as growth hormone insensitivity syndrome (MIM-262500). Here we represent a consanguineous Pakistani family in which three siblings were afflicted with LS. Patients had rather similar phenotypic presentations marked with short stature, delayed bone age, limited extension of elbows, truncal obesity, delayed puberty, childish appearance, and frontal bossing. They also had additional features such as hypo-muscularity, early fatigue, large ears, widely-spaced breasts, and attention deficit behavior, which are rarely reported in LS. The unusual combination of the features hindered a straightforward diagnosis and prompted us to first detect the regions of shared homozygosity and subsequently the disease-causing variant by next generation technologies, like SNP genotyping and exome sequencing. A homozygous pathogenic variant c.508G>C (p.(Asp170His)) in GHR was detected. The variant is known to be implicated in LS, supporting the molecular diagnosis of LS. Also, we present detailed clinical, hematological, and hormonal profiling of the siblings.


Asunto(s)
Síndrome de Laron , Pubertad Tardía , Humanos , Síndrome de Laron/genética , Síndrome de Laron/diagnóstico , Mutación/genética , Obesidad , Pakistán , Receptores de Somatotropina/genética
5.
Yale J Biol Med ; 96(3): 347-365, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37780999

RESUMEN

Intellectual disability (ID) involves compromised intellectual, learning and cognitive skills, and behavioral capabilities with reduced psychomotor skills. One of the preventable causes of ID is congenital hypothyroidism (CH), which may be due to biallelic mutations in thyroid peroxidase (TPO). In low- and middle-income countries with no newborn screening programs, CH poses a great risk of ID and long-term morbidity. We report two large Pakistani families with a total of 16 patients afflicted with CH. Detailed clinical and behavioral assessments, SNP-based homozygosity mapping, linkage analysis, and exome sequencing were performed. Initially, affected individuals were referred as suffering ID (in 11 of 16 patients) and developmental delay (in 14). Secondary/associated features were verbal apraxia (in 13), goiter (in 12), short stature (in 11), limb hypotonia (in 14), no pubertal onset (five of 10 of age ≥14 years), high myopia (in eight), muscle cramps (in six), and in some, variable microcephaly and enuresis/encopresis, fits, chronic fatigue, and other behavioral symptoms, which are not characteristics of CH. Molecular genetic analyses led to the discovery of homozygous variants in TPO: novel missense variant c.719A>G (p.Asp240Gly) in family 1 and rare c.2315A>G (p.Tyr772Cys) in family 2. In low-resource countries where neonatal screening programs do not include a CH test, the burden of neurodevelopmental disorders is likely to be increased due to untreated CH. Secondly, in the background of the high prevalence of recessive disorders due to high parental consanguinity, the severe manifestation of TPO-deficiency mimics a wide range of neurological and other presentations posing a diagnostic dilemma.


Asunto(s)
Hipotiroidismo Congénito , Discapacidad Intelectual , Adolescente , Niño , Humanos , Hipotiroidismo Congénito/complicaciones , Hipotiroidismo Congénito/diagnóstico , Hipotiroidismo Congénito/genética , Discapacidades del Desarrollo/diagnóstico , Discapacidades del Desarrollo/genética , Audición , Discapacidad Intelectual/diagnóstico , Discapacidad Intelectual/genética , Yoduro Peroxidasa/genética , Mutación/genética
6.
Yale J Biol Med ; 96(3): 383-396, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37781000

RESUMEN

Spondylocarpotarsal synostosis (SCT) syndrome is a very rare and severe form of skeletal dysplasia. The hallmark features of SCT are disproportionate short stature, scoliosis, fusion of carpal and tarsal bones, and clubfoot. Other common manifestations are cleft palate, conductive and sensorineural hearing loss, joint stiffness, and dental enamel hypoplasia. Homozygous variants in FLNB are known to cause SCT. This study was aimed to investigate the phenotypic and genetic basis of unique presentation of SCT syndrome segregating in a consanguineous Pakistani family. Three of the four affected siblings evaluated had severe short stature, short trunk, short neck, kyphoscoliosis, pectus carinatum, and winged scapula. The subjects had difficulty in walking and gait problems and complained of knee pain and backache. Roentgenographic examination of the eldest patient revealed gross anomalies in the axial skeleton including thoracolumbar and cervical fusion of ribs, severe kyphoscoliosis, thoracic and lumbar lordosis, coxa valga, fusion of certain carpals and tarsals, and clinodactyly. The patients had normal faces and lacked other typical features of SCT like cleft palate, conductive and sensorineural hearing loss, joint stiffness, and dental enamel hypoplasia. Whole exome sequencing (WES) of two affected siblings led to the discovery of a rare stop-gain variant c.220C>T (p.(Gln74*)) in exon 1 of the FLNB gene. The variant was homozygous and segregated with the malformation in this family. This study reports extensive phenotypic variability in SCT and expands the mutation spectrum of FLNB.


Asunto(s)
Fisura del Paladar , Hipoplasia del Esmalte Dental , Escoliosis , Animales , Humanos , Escoliosis/diagnóstico por imagen , Escoliosis/genética , Consanguinidad , Fenotipo , Filaminas/genética
7.
Cancer Treat Res ; 185: 177-205, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37306910

RESUMEN

Targeted therapy and personalized medicine are novel emerging disciplines of cancer research intended for treatment and prevention. One of the most significant advancements in modern oncology is the shift from an organ-centric strategy to a personalized strategy guided by deep molecular analysis. This shift in view, which focuses on the tumour's precise molecular changes, has paved the way for individualized treatment. Researchers and clinicians are using targeted therapies to select the best treatment available based on the molecular characterization of malignant cancer. In the treatment of a cancer, personalized medicine entails the use of genetic, immunological, and proteomic profiling to provide therapeutic alternatives as well as prognostic information about cancer. In this book, targeted therapies and personalized medicine have been covered for specific malignancies, including latest FDA-approved targeted therapies and it also sheds light on effective anti-cancer regimens and drug resistance. This will help to enhance our ability to conduct individualized health planning, make early diagnoses, and choose optimal medications for each cancer patient with predictable side effects and outcomes in a quickly evolving era. Various applications and tools' capacity have been improved for early diagnosis of cancer and the growing number of clinical trials that choose specific molecular targets reflects this predicament. Nevertheless, there are several limitations that must need to be addressed. Hence, in this chapter, we will discuss recent advancements, challenges, and opportunities in personalized medicine for various cancers, with a specific emphasis on target therapies in diagnostics and therapeutics.


Asunto(s)
Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Medicina de Precisión , Estados Unidos , Humanos , Proteómica , Planificación en Salud , Oncología Médica
8.
Cancer Treat Res ; 185: 207-235, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37306911

RESUMEN

Considerable advances in the field of cancer have been made; however, these have not been translated into similar clinical progress which results in the high prevalence and increased cancer-related mortality rate worldwide. Available treatments have several challenges such as off-target side effects, non-specific long-term potential biodisruption, drug resistance, and overall inadequate response rates and high probability of recurrence. The limitations associated with independent cancer diagnosis and therapy can be minimized by an emerging interdisciplinary research field of nanotheranostics which include successful integration of diagnosis and therapy on a single agent using nanoparticles. This may offer a powerful tool in developing innovative strategies to enable "personalized medicine" for diagnosis and treatment of cancer. Nanoparticles have been proven to be powerful imaging tools or potent agents for cancer diagnosis, treatment, and prevention. The nanotheranostic provides minimally invasive in vivo visualization of drug biodistribution and accumulation at the target site with real-time monitoring of therapeutic outcome. This chapter intends to cover several important aspects and the advances in the field of nanoparticles-mediated cancer therapeutics including nanocarrier development, drug/gene delivery, intrinsically active nanoparticles, tumor microenvironment, and nanotoxicity. The chapter represents an overview of challenges associated with cancer treatment, rational for nanotechnology in cancer therapeutics, novel concepts of multifunctional nanomaterials for cancer therapy along with their classification and their clinical prospective in different cancers. A special focus is on the nanotechnology: regulatory perspective for drug development in cancer therapeutics. Obstacles hindering further development of nanomaterials-mediated cancer therapy are also discussed. In general, the objective of this chapter is to improve our perceptive in the design and development of nanotechnology for cancer therapeutics.


Asunto(s)
Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Neoplasias , Humanos , Estudios Prospectivos , Distribución Tisular , Medicina de Precisión , Microambiente Tumoral
9.
Open Life Sci ; 17(1): 321-322, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35480483

RESUMEN

With the onset of coronavirus disease in December 2019, the normal routine and lifestyle of the humans has adversely affected all over the world. This change in lifestyle not only increased the level of stress and anxiety, but also badly modified the eating habits during the lockdown period. This increased the rate of binge eating disorder in people who were already immune-compromised. This rapid communication aims to develop awareness among people to stay calm during this pandemic and eat healthy.

10.
EMBO J ; 41(2): e105531, 2022 12 17.
Artículo en Inglés | MEDLINE | ID: mdl-34904718

RESUMEN

Recessive gene mutations underlie many developmental disorders and often lead to disabling neurological problems. Here, we report identification of a homozygous c.170G>A (p.Cys57Tyr or C57Y) mutation in the gene coding for protein disulfide isomerase A3 (PDIA3, also known as ERp57), an enzyme that catalyzes formation of disulfide bonds in the endoplasmic reticulum, to be associated with syndromic intellectual disability. Experiments in zebrafish embryos show that PDIA3C57Y expression is pathogenic and causes developmental defects such as axonal disorganization as well as skeletal abnormalities. Expression of PDIA3C57Y in the mouse hippocampus results in impaired synaptic plasticity and memory consolidation. Proteomic and functional analyses reveal that PDIA3C57Y expression leads to dysregulation of cell adhesion and actin cytoskeleton dynamics, associated with altered integrin biogenesis and reduced neuritogenesis. Biochemical studies show that PDIA3C57Y has decreased catalytic activity and forms disulfide-crosslinked aggregates that abnormally interact with chaperones in the endoplasmic reticulum. Thus, rare disease gene variant can provide insight into how perturbations of neuronal proteostasis can affect the function of the nervous system.


Asunto(s)
Discapacidades del Desarrollo/genética , Retículo Endoplásmico/metabolismo , Proteína Disulfuro Isomerasas/genética , Proteostasis , Adolescente , Adulto , Animales , Axones/metabolismo , Axones/patología , Adhesión Celular , Células Cultivadas , Niño , Citoesqueleto/metabolismo , Discapacidades del Desarrollo/metabolismo , Discapacidades del Desarrollo/patología , Femenino , Hipocampo/metabolismo , Hipocampo/patología , Humanos , Integrinas/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Mutación Missense , Proyección Neuronal , Plasticidad Neuronal , Linaje , Proteína Disulfuro Isomerasas/metabolismo , Pez Cebra
11.
Saudi J Biol Sci ; 28(11): 6615-6620, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34764777

RESUMEN

BACKGROUND: Acne is an inflammatory condition principally affected by genetic and dietary factors. Investigation into functional polymorphisms of TNF-α gene and their association with acne vulgaris will be helpful in exploring genetic influence on skin immune mediated inflammatory events. In the present study, we analyzed association of TNF-α gene polymorphisms, its expression levels and lipid profiles in a large cohort of acne patients and controls. METHODS: We used PCR-RFLP to study association of TNF-α polymorphisms at -857C/T, -863C/A and -1031 T/C sites with acne vulgaris. Lipid profiles were measured using enzymatic end-point method. The serum levels of TNF-α and apolipoprotein a were measured using ELISA. NIH, LDlink was used to investigate patterns of linkage disequilibrium across south Asian reference genome (Punjabi from Lahore Pakistan). RESULTS: We found that TNF-α -863 polymorphism is strongly associated with acne in overall population as well as in gender and severity based groups of acne patients. Polymorphisms at -863 and -1031 position were in linkage disequilibrium. Importantly, TNF-α serum level was significantly increased in acne patients with severe disease symptoms. Furthermore, levels of total cholesterol (TC) and triglycerides (TG) were significantly increased, whereas high density lipoprotein cholesterol (HDL-C) level was significantly decreased in acne patients. The levels of apolipoprotein a varied widely in studied populations and no significant difference was found in the analyzed groups. CONCLUSION: In conclusion, we found that TNF-α expression increases in acne patients affected by TNF-α polymorphisms, and that the lipid profile is specifically disrupted in acne patients.

12.
Eur J Med Genet ; 63(9): 103926, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32325225

RESUMEN

Tooth agenesis (TA) is the developmental absence of one or more permanent teeth. We report on 10 members of a Pakistani family afflicted with TA with variable associated features inherited in autosomal dominant fashion with full penetrance. The malformation is bilateral in the majority of cases, and hallmark feature is the absence of lateral and central incisors and canines whereas first and second premolars are involved less often. Affected individuals also have pronounced variable features associated with TA such as diastema between central incisors, overgrown labial frenum, peg-shaped lower incisors, delayed exfoliation, over-erupted upper incisors and malocclusion but have no other signs of ectodermal dysplasia. Through linkage analysis coupled with exome sequencing, we identified novel nonsense variant EDAR c.1302G>A, p.(Trp434*). The variant is deduced to create a premature termination codon that leads to the deletion of the 15 C-terminal residues. Heterozygous EDAR variants most commonly cause hypohydrotic ectodermal dysplasia, but recently one nonsense and 10 missense variants have been reported in nonsyndromic TA, some with few mild features of hypohydrotic ectodermal dysplasia. The phenotype in the family we present, the largest with EDAR-related TA reported to date, is highly variable and without any signs of ectodermal dysplasia.


Asunto(s)
Anodoncia/genética , Codón sin Sentido , Receptor Edar/genética , Adolescente , Adulto , Anodoncia/patología , Niño , Femenino , Genes Dominantes , Heterocigoto , Humanos , Masculino , Linaje , Fenotipo
13.
J Med Genet ; 55(3): 189-197, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29127258

RESUMEN

BACKGROUND: Bardet-Biedl syndrome (BBS) is a ciliopathy with extensive phenotypic variability and genetic heterogeneity. We aimed to discover the gene mutated in a consanguineous kindred with multiple cases of a BBS phenotype. METHODS: SNP genotype data were used for linkage analysis and exome sequencing to identify mutations. Modelling and in silico analysis were performed to predict mutation severity. RESULTS: Patients had postaxial polydactyly plus variable other clinical features including rod-cone dystrophy, obesity, intellectual disability, renal malformation, developmental delay, dental anomalies, speech disorder and enlarged fatty liver. The 4.57 Mb disease locus harboured homozygous, truncating CEP19 c.194_195insA (p.Tyr65*) mutation. We also found glioma-associated oncogene homolog 1(GLI1) c.820G>C (p.Gly274Arg) in the homozygous state in most patients. In silico modelling strongly suggests that it is damaging. Also, different combinations of four possible modifier alleles in BBS-related genes were detected. Two are known modifier alleles for BBS, splicing variant CCDC28B c.330C>T and missense MKKS/BBS6 p.Ile339Val, and the others are C8ORF37/BBS21 p.Ala178Val and TMEM67/BBS14 modifier p.Asp799Asp. Some patients carry all those five known/possible modifier alleles. Such variants are highly significantly more abundant in our patients than in a control group. CONCLUSION: CEP19 encodes a centrosomal and ciliary protein, as all BBS genes do. Another truncating mutation p.Arg82* has been reported as responsible for morbid obesity in a family; however, in the family we present, not all homozygotes are obese, although some are severely obese. The variant in GLI1, encoding a transcription factor that localises to the primary cilium and nucleus and is a mediator of the sonic hedgehog pathway, possibly exacerbates disease severity when in the homozygous state.


Asunto(s)
Síndrome de Bardet-Biedl/genética , Proteínas de Ciclo Celular/genética , Dedos/anomalías , Obesidad Mórbida/genética , Polidactilia/genética , Dedos del Pie/anomalías , Proteína con Dedos de Zinc GLI1/genética , Adolescente , Adulto , Síndrome de Bardet-Biedl/complicaciones , Síndrome de Bardet-Biedl/patología , Femenino , Dedos/patología , Ligamiento Genético , Homocigoto , Humanos , Masculino , Persona de Mediana Edad , Mutación , Obesidad Mórbida/patología , Polidactilia/complicaciones , Polidactilia/patología , Polimorfismo de Nucleótido Simple/genética , Dedos del Pie/patología , Secuenciación del Exoma/métodos , Adulto Joven
14.
Am J Med Genet A ; 173(9): 2494-2499, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28636205

RESUMEN

We report on nine members of a consanguineous Pakistani family with primary presentation of intellectual disability, developmental delay, limb and gait ataxia, behavioral and speech problems, and tremor. By linkage mapping and exome sequencing we identified novel homozygous splicing variant c.6375-1G>C in SPTBN2. To date, only two other SPTBN2 mutations with recessive pattern of inheritance causing SCAR14 (spinocerebellar ataxia, autosomal recessive 14) that manifest with developmental ataxia and cognitive impairment, or cerebellar ataxia, mental retardation, and pyramidal signs have been reported. The mutation we identified is predicted to lead to the deletion of just the pleckstrin homology domain; thus, the earlier onset and more progressive nature of the disease in the presented family, as compared to earlier reports, were unexpected. No other mutation that could possibly explain the features that were unusual for SCAR14-arched palate, limb hypotonia, climacophobia, and behavioral problems-was identified. The disease was more severe in males than females. Our findings expand the recessive SPTBN2 mutation phenotype. We also review SPTBN2 mutation phenotypes. The gene encodes beta-III spectrin, which forms tetramers with alpha-II spectrin. The manifestations of this third recessive mutation suggest that for recessive mutations either no mutant protein is synthesized because the transcript is subject to nonsense-mediated decay or the mutant protein does not bind membrane proteins and, thus, does not exert a negative effect in heterozygotes, whereas the dominant mutations causing SCA5 form defective tetramers that compete with the native tetramers in binding membrane proteins, but are unable to anchor them.


Asunto(s)
Discapacidades del Desarrollo/genética , Espectrina/genética , Ataxias Espinocerebelosas/genética , Temblor/genética , Adolescente , Adulto , Niño , Preescolar , Discapacidades del Desarrollo/fisiopatología , Femenino , Homocigoto , Humanos , Trastornos del Desarrollo del Lenguaje/genética , Trastornos del Desarrollo del Lenguaje/fisiopatología , Imagen por Resonancia Magnética , Masculino , Fenotipo , Problema de Conducta , Eliminación de Secuencia , Ataxias Espinocerebelosas/diagnóstico por imagen , Ataxias Espinocerebelosas/fisiopatología , Temblor/fisiopatología , Adulto Joven
15.
Eur J Med Genet ; 60(5): 268-274, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28315472

RESUMEN

Polydactyly is a phenotypically and genetically highly heterogeneous limb malformation with preaxial and postaxial subtypes and subtypes A and B. Most polydactyly entities are associated with GLI3 mutation. We report on 10 affected individuals from a large Pakistani kindred initially evaluated as a possible new condition. The phenotype is postaxial polydactyly types A and B associated with zygodactyly, postaxial webbing of toes and additional features not previously reported for isolated polydactyly such as camptodactyly, hypoplasia of third toe, and wide space between hallux and second toe. Hypothesizing that the disorder could have resulted from a mutation in a novel gene responsible for polydactyly, we launched a genetic investigation. By linkage mapping and exome sequencing in the most severe case, we identified novel heterozygous frameshift mutation NM_000168.5 (GLI3): c.3635delG (p.(Gly1212Alafs*18)) but did not detect any other possibly deleterious mutation that could explain the unusual features of camptodactyly, hypoplasia of third toe and wide space between first and second toes. Our findings further expand the phenotypic variability of GLI3 polydactyly. We also present a review of GLI3-associated isolated limb anomalies, which indicates that GLI3 mutation leads primarily to two well-established polydactyly types: postaxial types A and B and crossed polydactyly type I. In addition, a variety of other minor digit anomalies generally accompany polydactyly, and there is no straightforward genotype-polydactyly phenotype correlation.


Asunto(s)
Factores de Transcripción de Tipo Kruppel/genética , Mutación , Proteínas del Tejido Nervioso/genética , Polidactilia/genética , Dedos del Pie/anomalías , Femenino , Humanos , Masculino , Pakistán , Linaje , Proteína Gli3 con Dedos de Zinc
16.
Am J Med Genet A ; 167A(12): 3148-52, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26333564

RESUMEN

Primary microcephaly is clinically variable and genetically heterogeneous. Four phenotypically distinct types of autosomal recessive microcephaly syndromes are due to different RBBP8 mutations. We report on a consanguineous Pakistani family with homozygous RBBP8 mutation c.1808_1809delTA (p.Ile603Lysfs*7) manifesting microcephaly and a distinct combination of skeletal, limb and ectodermal defects, mild intellectual disability, minor facial anomalies, anonychia, disproportionate short stature and brachydactyly, and additionally talipes in one patient.


Asunto(s)
Braquidactilia/genética , Proteínas Portadoras/genética , Enanismo/genética , Discapacidad Intelectual/genética , Microcefalia/genética , Mutación/genética , Proteínas Nucleares/genética , Adolescente , Adulto , Braquidactilia/patología , Consanguinidad , Enanismo/patología , Endodesoxirribonucleasas , Femenino , Homocigoto , Humanos , Discapacidad Intelectual/patología , Masculino , Microcefalia/patología , Linaje , Fenotipo , Pronóstico , Síndrome , Adulto Joven
17.
Pak J Med Sci ; 31(6): 1542-4, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26870132

RESUMEN

Grebe syndrome (OMIM-200700) is a very rare type of acromesomelic dysplasia with autosomal recessive inheritance. We studied a Pakistani family with two affected individuals having typical features of Grebe chondrodysplasia. Patients were observed with short and deformed limbs having a proximo-distal gradient of severity. Hind-limbs were more severely affected than fore-limbs. Digits on autopods were very short and nonfunctional. Index subject also had nearsightedness. However, symptoms in the craniofacial and axial skeleton were minimal. Genetic analysis revealed four base pair insertion mutation (c.1114insGAGT) in gene coding cartilage-derived morphogenetic protein-1 (CDMP1). This mutation was predicted to cause premature stop codon. The clinical presentation in this study broadens the range of phenotypes associated with CDMP1 mutation in Pakistani population.

18.
Am J Hum Genet ; 95(6): 649-59, 2014 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-25466284

RESUMEN

Mesoaxial synostotic syndactyly, Malik-Percin type (MSSD) (syndactyly type IX) is a rare autosomal-recessive nonsyndromic digit anomaly with only two affected families reported so far. We previously showed that the trait is genetically distinct from other syndactyly types, and through autozygosity mapping we had identified a locus on chromosome 17p13.3 for this unique limb malformation. Here, we extend the number of independent pedigrees from various geographic regions segregating MSSD to a total of six. We demonstrate that three neighboring missense mutations affecting the highly conserved DNA-binding region of the basic helix-loop-helix A9 transcription factor (BHLHA9) are associated with this phenotype. Recombinant BHLHA9 generated by transient gene expression is shown to be located in the cytoplasm and the cell nucleus. Transcription factors 3, 4, and 12, members of the E protein (class I) family of helix-loop-helix transcription factors, are highlighted in yeast two-hybrid analysis as potential dimerization partners for BHLHA9. In the presence of BHLHA9, the potential of these three proteins to activate expression of an E-box-regulated target gene is reduced considerably. BHLHA9 harboring one of the three substitutions detected in MSSD-affected individuals eliminates entirely the transcription activation by these class I bHLH proteins. We conclude that by dimerizing with other bHLH protein monomers, BHLHA9 could fine tune the expression of regulatory factors governing determination of central limb mesenchyme cells, a function made impossible by altering critical amino acids in the DNA binding domain. These findings identify BHLHA9 as an essential player in the regulatory network governing limb morphogenesis in humans.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Dedos/anomalías , Mutación Missense , Sindactilia/genética , Dedos del Pie/anomalías , Secuencia de Aminoácidos , Sitios de Unión , Análisis Mutacional de ADN , Dimerización , Femenino , Genes Reporteros , Genotipo , Haplotipos , Humanos , Italia , Masculino , Persona de Mediana Edad , Pakistán , Linaje , Fenotipo , Unión Proteica , Estructura Terciaria de Proteína , Alineación de Secuencia , Turquía , Adulto Joven
19.
Pak J Med Sci ; 30(6): 1428-31, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25674153

RESUMEN

Congenital hypoplasia of thumb is rare malformation which is less likely to appear as an isolated entity. Four independent subjects exhibiting various grades of underdeveloped first digital ray were recruited. The affected autopods had narrow palms, medial or valgus inclinations of index fingers and thenar weakness, while the postaxial digits were least affected. According to the classification of hypoplastic thumb by Blauth and Schneider-Sickert (1981), the phenotypes were concordant with types 3 and 4. In one of the subjects there was contralateral preaxial polydactyly. All cases were sporadic and nonsyndromic and parental consanguinity was witnessed in two individuals. Recurrent appearance of similar phenotypes may suggest genetic etiologies which should be elucidated with the help of high-throughput genetic methods.

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