Purpose
Congenital Adrenal Hyperplasia (CAH) is one of the highly prevalent autosomal recessive endocrine disorders. The majority of CAH cases result from mutations in the
CYP21A2
gene, leading to ...21-hydroxylase deficiency. However, with the pseudogene-associated challenges in
CYP21A2
gene analysis, routine genetic diagnostics and carrier screening in CAH are not a part of the first-tier investigations in a clinical setting. Furthermore, there is a lack of data on the carrier frequency for 21-OH deficiency. Therefore, this study is aimed at investigating the carrier frequency of common pseudogene derived
CYP21A2
mutations in Southern India.
Methods
Recently, a cost-effective Allele-specific PCR based genotyping for
CYP21A2
hotspot mutations has been demonstrated to be a highly specific and sensitive assay at the authors’ center. Leveraging this approach, a total of 1034 healthy individuals from South India underwent screening to identify the carrier frequency of nine hotspot mutations in the
CYP21A2
gene.
Results
In this study, it was observed that 9.76% of the subjects were carriers for one or more of the nine different
CYP21A2
mutations. Among the carriers, the most common was the large 30 kb deletion, followed by II72N, E6 CLUS, and I2G mutations.
Conclusion
We have identified a high prevalence of
CYP21A2
mutation carriers in Southern India. These findings emphasize the importance of implementing and expanding cost-effective genetic diagnostics and carrier screening throughout India. Such initiatives would play a crucial role in managing the disease burden, enabling early intervention, and establishing guidelines for CAH newborn genetic screening in the country. This study represents the first carrier screening data on
CYP21A2
hotspot mutations from India and is the largest study conducted till date in this context.
Cockayne syndrome (CS) is a rare, autosomal-recessive disorder characterized by microcephaly, impaired postnatal growth, and premature pathological aging. It has historically been considered a DNA ...repair disorder; fibroblasts from classic patients often exhibit impaired transcription-coupled nucleotide excision repair. Previous studies have largely been restricted to case reports and small series, and no guidelines for care have been established.
One hundred two study participants were identified through a network of collaborating clinicians and the Amy and Friends CS support groups. Families with a diagnosis of CS could also self-recruit. Comprehensive clinical information for analysis was obtained directly from families and their clinicians.
We present the most complete evaluation of Cockayne syndrome to date, including detailed information on the prevalence and onset of clinical features, achievement of neurodevelopmental milestones, and patient management. We confirm that the most valuable prognostic factor in CS is the presence of early cataracts. Using this evidence, we have created simple guidelines for the care of individuals with CS. We aim to assist clinicians in the recognition, diagnosis, and management of this condition and to enable families to understand what problems they may encounter as CS progresses.
Abstract
Bartter syndrome is a group of autosomal recessive renal tubular disorders; it has two types of presentation: antenatal and classic. The antenatal type presents as severe unexplained ...polyhydramnios in the second trimester. This is due to fetal urinary losses of sodium, chloride, and potassium, leading to fetal polyuria. The classic type presents in the late neonatal or infancy stage, with dehydration, dyselectrolytemia, failure to thrive, and nephrocalcinosis. Antenatal scans are normal in such cases. Type I and II Bartter syndrome presents in the antenatal period, whereas type IV has a classic presentation. We describe an unusual case of type IVa Bartter syndrome presenting in the antenatal period, with severe polyhydramnios. The initial diagnosis was made based on amniotic fluid chloride levels and later confirmed by performing a genetic test. Genetic testing is important for confirming diagnosis and prognostication regarding the condition.
Adult-onset leukodystrophies though individually rare are not uncommon. This group includes several disorders with isolated adult presentations, as well as several childhood leukodystrophies with ...attenuated phenotypes that present at a later age. Misdiagnoses often occur due to the clinical and radiological overlap with common acquired disorders such as infectious, immune, inflammatory, vascular, metabolic, and toxic etiologies. Increased prevalence of non-specific white matter changes in adult population poses challenges during diagnostic considerations. Clinico-radiological spectrum and molecular landscape of adult-onset leukodystrophies have not been completely elucidated at this time. Diagnostic approach is less well-standardized when compared to the childhood counterpart. Absence of family history and reduced penetrance in certain disorders frequently create a dilemma. Comprehensive evaluation and molecular confirmation when available helps in prognostication, early initiation of treatment in certain disorders, enrollment in clinical trials, and provides valuable information for the family for reproductive counseling. In this review article, we aimed to formulate an approach to adult-onset leukodystrophies that will be useful in routine practice, discuss common adult-onset leukodystrophies with usual and unusual presentations, neuroimaging findings, recent advances in treatment, acquired mimics, and provide an algorithm for comprehensive clinical, radiological, and genetic evaluation that will facilitate early diagnosis and consider active treatment options when available. A high index of suspicion, awareness of the clinico-radiological presentations, and comprehensive genetic evaluation are paramount because treatment options are available for several disorders when diagnosed early in the disease course.
SERPINF1 gene variants lead to a severe type of osteogenesis imperfecta (OI) attributed to defects in the matrix mineralization. We present 18 patients with SERPINF1 gene variants leading to severe ...progressive deforming OI, the largest series in the world to date. These patients were normal at birth and had the first fracture between 2 months to 9 years; progression of deformities was seen in 12 adolescents who became nonambulatory. Radiologically, compression fractures with kyphoscoliosis, protrusio acetabuli, and lytic lesions in the metaphysis and pelvis were seen in older children with classical popcorn appearance in the distal femoral metaphysis in three. By exome sequencing and targeted sequencing, we identified ten variants. One was unreported and novel; three other novel variants in this series were reported earlier. The recurrent deletion inframe mutation p.phe277del was found in 5 patients from three families. Alkaline phosphatase was elevated in all children on the first visit. Bone mineral density was low in all patients and showed improvement at two years in seven children on regular pamidronate therapy. For others, the 2 year BMD data were not available. The Z scores for four of the seven children showed worsening at the 2-year follow-up.
Introduction
Alkaptonuria (AKU) is a rare metabolic disease. The global incidence is 1:100,000 to 1:250,000. However, identification of a founder mutation in a gypsy population from India prompted us ...to study the prevalence of AKU in this population and to do molecular typing in referred cases of AKU from the rest of India.
Objective
To determine the prevalence of AKU in the gypsy population predominantly residing in the seven districts of Tamil Nadu. To determine the molecular characteristic of AKU cases referred to our clinic from various parts of India.
Method
Urine spot test to detect homogentisic acid followed by quantitative estimation using high-performance liquid chromatography in 499 participants from the gypsy population and confirming the founder mutation in those with high levels by sequencing. Sequence the homogentisate 1,2-dioxygenase (HGD) gene to identify mutations and variants in 29 AKU non-gypsy cases.
Results
The founder mutation was detected in homozygous state in 41/499 AKU-affected individuals of the gypsy community giving a high prevalence of 8.4%. Low back pain, knee pain, and eye and ear pigmentation were the most common symptoms and signs respectively. The commonest mutation identified in the non-gypsy AKU cases was p.Ala122Val.
Conclusion
High prevalence of AKU in the inbred gypsy population at 8.4% was detected confirming the founder effect. Urine screening provided a cost-effective method to detect the disease early. Mutation spectrum is varied in the rest of the Indian population. This study identified maximum number of mutations in exon 6 of the HGD gene.
Key Points
• High prevalence (8.4%) of alkaptonuria (AKU) in the gypsy population due to founder mutation in the HGD gene.
•
Inbreeding exemplifies the founder effects of this rare genetic disorder.
•
Urinary screening is a cost-effective method in this community for early detection of AKU and intervention.
• The mutation spectrum causing AKU is diverse in the rest of the Indian population.
Background: Status dystonicus (SD) is a life-threatening movement disorder emergency characterized by increasingly frequent and severe episodes of generalized dystonia, requiring urgent hospital ...admission. The diverse clinico-etiological spectrum, high risk of recurrence, and residual disabilities complicate functional outcomes. Aim: We aim to describe the clinico-etiological spectrum, radiology, therapeutic options, and follow-up of patients with pre-status dystonicus (pre-SD) and SD. Methodology: A cross-sectional retrospective study was carried out in a tertiary care referral center. The clinical, laboratory, and radiology data of all patients aged less than 18 years with pre-SD and SD from January 2010 to December 2020 were collected. The Dystonia Severity Assessment Plan (DSAP) scale for grading severity and the modified Rankin Scale (mRS) for assessing outcome were used at the last follow-up visit. Results: Twenty-eight patients (male:female: 2.1:1) experiencing 33 episodes of acute dystonia exacerbation were identified. The median age at the onset of dystonia and SD presentation was 8.71 (range: 0.25-15.75) and 9.12 (range: 1-16.75) years, respectively. Four patients experienced more than one episode of SD. The etiological spectrum of SD includes metabolic (Wilson's disease-13, L-aromatic amino acid decarboxylase deficiency-one, and Gaucher's disease-one), genetic (neurodegeneration with brain iron accumulation-three and KMT2B and THAP 1 gene-related-one each), structural-three, post-encephalitic sequelae (PES)-four, and immune-mediated (anti-NMDA receptor encephalitis-one). Five patients had pre-SD (DSAP grade 3), and 23 patients had established SD (DSAP grade 4-17 and DSAP grade 5-six). The Rapid escalation of chelation therapy precipitated SD in 11 patients with Wilson's disease. Febrile illness or pneumonia precipitated SD in nine patients. Twenty-three episodes of SD required midazolam infusion in addition to anti-dystonic medications. The median duration of hospital stay was 10 days (range: 3-29). Twenty-three patients had resolution of SD but residual dystonia persisted, while two patients had no residual dystonia at follow-up. Three patients succumbed owing to refractory SD and its complications. Conclusion: Early identification of triggers, etiology, and appropriate management are essential to calm the dystonic storm.
Assessment of disease activity in Takayasu arteritis (TA) is challenging. We aimed to study utility of serum amyloid A (SAA) to assess disease activity and its association with SAA gene ...polymorphisms, if any, in our TA patients. Serum of 99 consecutive adult TA patients and 40 healthy controls were assayed for SAA. Depending on the ITAS2010 and ITAS-CRP score, patients were designated as having active disease if ITAS2010 ≥ 2 or ITAS-CRP ≥ 3 and stable disease if ITAS2010 = 0 or ITAS-CRP is ≤1. Clinical ITAS of 0 with raised inflammatory markers scoring a ITAS-CRP of 2 was considered as indeterminate for disease activity assessment. Repeat SAA levels for active group was measured after 6 months from baseline. SAA levels between active and stable disease as well as serial levels were compared. DNA of 40 patients and controls were genotyped for SAA polymorphisms (rs12218, rs2468844) and the allele frequencies were compared. At baseline, SAA levels were higher in patients as compared to controls (137.4 vs 100.8 ng/ml,
p
= 0.001) and higher in patients with active disease (166.4 ng/ml) than those with stable disease (98.2 ng/ml),
p
= 0.001. SAA decreased during follow-up in treatment responders (189.9 ng/ml at baseline vs 119.0 ng/ml at follow-up,
p
= 0.008); in contrast, there was no significant change among non-responders during follow-up. Allelic frequencies of SAA gene polymorphisms did not differ between cases and controls. SAA may be a reliable biomarker to assess disease activity and treatment response in TA.
Background: Arginase deficiency is considered a masquerader of diplegic cerebral palsy. The rarity of hyperammonemic crisis and the slowly progressive course has made it a unique entity among the ...urea cycle defects. Objectives: The aim of our study is to describe the varied phenotypic spectrum of children with arginase deficiency. Methodology: This retrospective study included children and adolescents aged <18 years with a biochemical or genetic diagnosis of arginase deficiency from May 2011 to May 2022. Data were collected from the hospital's electronic database. The clinical presentation, laboratory parameters at baseline and during metabolic decompensation, neuroimaging, electroencephalography findings, and molecular studies were analyzed. Results: About 11 children from nine families with biochemically or genetically proven arginase deficiency were analyzed. The male: female ratio was 2.7:1. Consanguineous parentage was observed in all children. The median age at presentation was 36 months (Range: 5 months-18 years). All children with onset of symptoms in early childhood had a predominant delay in motor milestones of varying severity. Metabolic decompensation with encephalopathy occurred in all except two children (n = 9, 81.8%). Pyramidal signs were present in all patients and additional extrapyramidal signs in two children. Positive family history was present in four probands. Seizures occurred in all children. Epilepsy with electrical status in slow wave sleep and West syndrome was noted in three children. All children had elevated ammonia and arginine at the time of metabolic crisis. The spectrum of neuroimaging findings includes periventricular, subcortical, and deep white matter signal changes and diffusion restriction. The mean duration of follow-up was 38.6 ± 34.08 months. All patients were managed with an arginine-restricted diet and sodium benzoate with or without ornithine supplementation. Conclusion: Spastic diparesis, recurrent encephalopathy, presence of family history, and elevated serum arginine levels must alert the clinician to suspect arginase deficiency. Atypical presentations in our cohort include frequent metabolic crises and epileptic encephalopathy. Early identification and management will ensure a better neurodevelopmental outcome.
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