Two cases of Christianson syndrome caused by SLC9A6 gene mutation / 中华神经科杂志

Christianson syndrome is a rare X-linked disease caused by mutations in the SLC9A6 gene. The clinical manifestations are male developmental delay, language disorder, seizures, mental retardation, ataxia, microcephaly and so on. Two cases of male children with Christianson syndrome were reported. The proband was 1 year and 11 months old. Clinical manifestations include microcephaly, global developmental delay, and seizures. The electroencephalogram showed that the central midline region of spikes and slow waves were emitted, and all exons sequencing detected a mutation in the SLC9A6 gene chrX: 135084373 [c.803+1(IVS6)G>A]. The proband′s brother was 4 years and 8 months old. The clinical manifestations were similar. The electroencephalogram showed spikes and spines in the Rolandic area on both sides. Slow waves and spiny slow waves were emitted. Magnetic resonance imaging suggested brain atrophy. The genetic verification results were consistent with the proband. The SLC9A6 gene c.803+1(IVS6) G>A splicing mutation was a pathogenic mutation in this family.

Late ophthalmology findings in a X-linked juvenile retinoschisis patient / Achados oftalmológicos tardios em um paciente portador de retinosquise juvenil ligada ao cromossomo X

ABSTRACT X-linked juvenile retinoschisis (XLRS) is a vitreoretinal degeneration caused by mutations in the RS1 gene, generally characterized by bilateral maculopathy and peripheral retinoschisis leading to progressive visual loss during the first 2 decades of life and complications like retinal detachment and vitreous hemorrhage. Herein, we present late ophthalmology findings in a XLRS patient.

RESUMO A retinosquise juvenil ligada ao cromossomo X (XLRS) é uma degeneração vitreorretiniana causada por mutações no gene RS1, geralmente caracterizada por maculopatia bilateral e retinosquise periférica, levando à perda visual progressiva durante as primeiras 2 décadas de vida e complicações como descolamento de retina e hemorragia vítrea. Apresentamos aqui achados oftalmológicos tardios em um paciente com XLRS.

Simpson-Golabi-Behmel syndrome type Ⅰ in neonates caused by GPC3 gene mutation: a case report and literature review / 中华围产医学杂志

Objective:To investigate the clinical and genetic characteristics of Simpson-Golabi-Behmel syndrome (SGBS) type Ⅰ caused by glypican-3 ( GPC3) gene mutations. Methods:Data of one neonate with SGBS type Ⅰ from Shenzhen Maternity and Child Healthcare Hospital Affiliated to Southern Medical University was reviewed retrospectively. Literature was retrieved to summarize the clinical and genetic characteristics of SGBS type Ⅰ caused by GPC3 mutations, using terms of "Simpson-Golabi-Behmel type Ⅰ", "GPC3" and "glypican-3" from China National Knowledge Infrastructure, VIP database, Wanfang database, and PubMed from January 2010 till April 2021. Results:The male infant was admitted to the hospital at 4 h after birth due to "abdominal distension for 1 h", presenting with dysmorphic facial features, including macrocephaly, coarse face, broad nasal bridge, macrostomia, tongue with a groove in the middle, as well as macrosomatia, supernumerary nipples, and hypospadias. Whole exome sequencing revealed a novel frameshift mutation (c.720delC) in GPC3 gene of the patient and his mother for hemizygous and heterozygous variation, respectively, based on which SGBS type Ⅰwas confirmed. During the follow-up, overgrowth, neuroblastoma, and motor development retardation were found in the boy. In addition to the index patient, 92 cases of SGBS type Ⅰ reported in 31 articles were analyzed, including 89(95.7%) males and 4(4.3%) females. The main clinical features were craniofacial dysmorphism, pre/postnatal overgrowth with multiple congenital anomalies. Most patients were combined with language disorders, motor retardation, and various degrees of dysnoesia, and were more likely to develop embryonic tumors. Among the 93 cases, 11(11.8%) suffered from tumors. Apart from 21 cases of termination, 63 cases were born alive and nine cases died after birth. Pathogenic variants in GPC3 gene were reported in 80 cases, which were nonsense mutation in 25 cases (31.2%), DNA fragment deletion in 21 cases (26.2%), frameshift mutation in 16 cases (20.0%), large duplications in eight cases (10.0%), missense mutation in five cases(6.2%), and splice site mutation in five cases(6.2%). Conclusions:SGBS type Ⅰ is an X-linked recessive genetic disease with various phenotypes. Patients with postnatal craniofacial dysmorphism, overgrowth, and multiple congenital anomalies should be highly suspected of SGBS type Ⅰ. Genetic testing is conducive to its early diagnosis. Treatment requires multidisciplinary cooperation and long-term follow-up, especially for those with tumors.

Analysis and literature review of COL4A5 mutation mosaicism in male patients with X-linked Alport syndrome / 中华肾脏病杂志

Objective:To report four male COL4A5 mutation mosaicism patients with X-linked Alport syndrome, and to provide evidence for diagnosis, genetic counseling, and reproduction in the respective families and improve our knowledge of mosaicism in Alport syndrome. Methods:Suspected male mosaic patients for COL4A5 who met the following criteria: clinical diagnosis of Alport syndrome, harbored COL4A5 mutations detected using next generation sequencing or Sanger sequencing, heterozygosity for the mutant and normal COL4A5 alleles in the DNA demonstrated by Sanger sequencing, registered in the on-line registry of hereditary kidney diseases, and admitted to Peking University First Hospital during the period of April 2018 to April 2019 were enrolled. Clinical data and karyotypes were retrospectively analyzed. Genetic DNA isolated from multiple tissues was analyzed for COL4A5 gene mutations by using PCR and Sanger sequencing. Related literatures published in PubMed, CNKI and Wanfang databases were reviewed. Results:Four COL4A5 somatic and germline mosaic male patients with Alport syndrome were included in the study. Patient 1 was characterized by hematuria and proteinuria. His karyotype of peripheral blood was normal. COL4A5 c.3455-1G>A mosaicism was detected in multiple tissues (peripheral blood, saliva and urine). Patient 2 presented with hematuria and microalbuminuria. His karyotype of peripheral blood was normal. COL4A5 c.4994+1G>A mosaicism was detected in multiple tissues (peripheral blood, saliva and skin fibroblasts). Patients 3 showed hematuria without proteinuria. COL4A5 c.3535G>A mosaicism was found in genomic DNA of peripheral blood and hair. Laboratory and physical examinations of patient 4 showed hematuria and normal renal function, without proteinuria, megasoma or small testes. COL4A5 c.3106G>A mosaicism was detected in genomic DNA of skin fibroblasts. Although without karyotype analysis due to unavailable specimens, 47,XXY or 46,XY/47,XXY mosaicism was not considered according to the reproductive history and lack of clinical manifestations of megasoma and small testes in patients 3 and 4. Renal disease in 8 published male cases with mosaicism for COL4A5 was affected by mutant allelic fractions and genotype. Conclusions:Compared with hemizygous males with X-linked Alport syndrome, the renal phenotype of mosaic males was milder, and associated with mutant allelic fractions and mutation type.

Study on the phenotype and genotype of X-linked adrenoleukodystrophy / 中华神经科杂志

Objective:To summarize the phenotype and genotype of X-linked adrenoleukodystrophy (X-ALD) patients, and compare the phenotype and genotype characteristics between children and adult patients.Methods:The comprehensive clinical data of 30 patients with X-ALD admitted to Beijing Jingdu Children′s Hospital and the First Medical Center of People′s Liberation Army General Hospital from August 2012 to December 2019 were analyzed, including their clinical manifestations and the results of gene test, biochemical test and magnetic resonance imaging examination, etc.Results:Among the 30 patients, 15 (50.0%) were childhood cerebraI ALD (CCALD, onset age 5－10 yeas, mean 7 years), 13 (43.3%) were adrenomyeloneuropathy (AMN, onset age 21－41 yeas, mean 29 years). One (3.3%) was adult cerebral ALD (onset age 29 yeas), one (3.3%) was pure Addison disease (onset age 3.5 yeas). Most common clinical phenotype in children was CCALD and the first symptoms were inattention, learning ability decline, vision and hearing impairment. Otherwise the most common type in adult was AMN and the first symptoms were mainly progressive weakness of the lower limbs, muscle spasm, and abnormal gait. These patients came from 29 different families, among whom, 25 patients conducted gene test and 22 different types of ABCD1 gene mutations were found. Missense mutation was the main gene mutation type. Patients with different clinical types had no specificity in gene mutation types.Conclusions:In China, the most common clinical classification of X-ALD in children is CCALD, and AMN in adults. No clear correlation has been found between genotype and phenotype.

Dystrophinopathy / 中华神经科杂志

Dystrophinopathy is a group of inherited diseases caused by the defect of dystrophin protein with X-linked recessive inheritance.The disease is clinically characterized by progressive severe muscles weakness and atrophy of proximal limb muscles and belt muscle,gastrocnemius pseudohypertrophy.The patient lose the ability of daily exercise,and ultimately succumb to restrictive lung disease or cardiac death.According to the clinical manifestations and the defect degree of dystrophin protein,dystrophinopathy is divided into:Duchenne muscular dystrophy (DMD),Becker muscular dystrophy,X-linked dilated cardiomyopathy,and female carrier of DMD.Patients can present with multi-system involvement at different stages of the disease,which require multidisciplinary management to alleviate symptoms,prolong life and improve quality of life.Glucocorticoids can significantly extend the independent activity of children by 2-5 years.Due to the high incidence,poor quality of life in the early stage and high disability and lethality in the late stage,it is important to strengthen the understanding of neurologists about this disease and conduct early diagnosis,full management and genetic counseling.

Diagnóstico molecular de distrofia muscular de Duchenne/Becker en una familia sin antecedentes patológicos de la enfermedad / Molecular Diagnosis of Duchenne/Becker muscular dystrophy in a family with no pathological antecedents of the disease

Fundamento: Las distrofias musculares de Duchenne y de Becker son enfermedades neuromusculares progresivas, con un patrón de herencia recesivo ligado al cromosoma X y causadas por mutaciones en el gen que codifica para la distrofina. El estudio de posibles portadoras en las familias afectadas resulta crucial, ya que genera expectativas y opciones frente al asesoramiento genético.Objetivos: describir el diagnóstico molecular de distrofia muscular de Duchenne/Becker en una familia sin antecedentes patológicos de la enfermedad.Métodos: se realizó un estudio experimental, de las deleciones en el gen distrofia muscular de Duchenne/Becker, en un paciente con diagnóstico clínico de la enfermedad, para lo cual se empleó la técnica de PCR-multiplex siguiendo los métodos descritos por Beggs y Chamberlain. También fueron estudiadas las mujeres de la familia, a través del análisis de marcadores polimórficos mediante repeticiones cortas en tándem de (CA)n.Resultados: fueron identificadas en el paciente deleciones de los exones 47 al 52; así como la procedencia del cromosoma X ligado a la enfermedad (abuelo materno). Se determinó el estado de no portadora en tres mujeres de la familia. No se pudo excluir mosaicismo germinal en la madre del niño.Conclusión: se infirió la ocurrencia de una mutación de novo. El diagnóstico molecular permitió la confirmación diagnóstica de la enfermedad en el niño afectado, además de la posibilidad de brindar un adecuado asesoramiento genético a la familia.

Foundation: Duchenne and  Becker muscular dystrophies are progressive neuromuscular diseases with a pattern of recessive inherited link to chromosome X and caused by mutations in the gene which codifies for dystrophin. The study of possible carriers in affected families is crucial since it generates expectations and options on genetic advisory.Objective: to describe the molecular diagnosis of Duchenne/Becker muscular dystrophy  in a family without pathological antecedents of the disease.Methods: an experimental study was developed about the deletions of Duchenne/Becker gene of muscular dystrophy, in a patient with clinical diagnosis of the disease. It was used multiple PCR technique following the methods described by Beggs and Chamberlain. In addition, the women of the family were studied by the analysis of polymorphic markers through short repetitions in (CA) n tandem.Results: deletions of exons from 47 to 52 were identified in the patient; so as the precedence of the X chromosome related to the disease (maternal grandfather). It was determined the state of non-carrier in three women of the family. It was not possible to exclude germline mosaicism in the child´s mother.Conclusion: the occurrence of a novo mutation was inferred. The molecular diagnosis allowed confirming the diagnosis of the affected child; in addition it was possible to offer adequate genetic advisory to the family.

Case report: is low α-Gal enzyme activity sufficient to establish the diagnosis of Fabry disease? / Relato de caso: a diminuição da enzimaα-Gal l é suficiente para estabelecer o diagnóstico?

Abstract Fabry disease is an X-linked lysosomal storage disease due to alpha-galactosidase A (α-Gal A) deficient activity which leads to the accumulation of glucoesphingolipids, such as globotriaosilceramide. There are over 700 known mutations of the enzyme gene, and most of them cause Fabry Disease. This case report describes a hemodialysis patient with a rare and controversial GLA gene mutation, the D313Y. The medecial investigation confirmed that D313Y is an alpha-galactosidase A sequence variant that causes pseudo deficient enzyme activity in plasma but not Fabry disease. Thus, clinical symptoms that prompted Fabry disease investigation could not be attributable to Fabry disease and therefore enzyme replacement therapy was not indicated.

Resumo Doença de Fabry (DF) é uma doença de depósito lisossômico ligada ao cromossomo X, causada pela deficiência da enzima alfa-galactosidase A (α-Gal A) que leva ao acúmulo de glicoesfingolipídeos, principalmente globotriaosilceramide. Existem mais de 700 mutações conhecidas do gene da enzima, a maioria delas são causadoras de DF. Este relato de caso descreve sobre um paciente em hemodiálise com uma mutação do gene GLA rara e controversa, a D313Y. A investigação médica confirmou que D313Y é uma variante que leva à pseudodeficiência plasmática da enzima, mas não ocasiona DF. Assim, os sintomas clínicos que induziram a investigação da doença não devem ser atribuídos à DF e, portanto, não foi indicada a terapia de reposição enzimática.

X-linked dominant protoporphyria:report of a pedigree and detection of ALAS2 gene mutations / 中华皮肤科杂志

Objective To report a pedigree with X?linked dominant protoporphyria(XLDPP), and to detect 5?aminolevulinic acid synthetase 2(ALAS2)gene mutations in this pedigree. Methods A clinical investigation was performed in a pedigree with XLDPP, and relevant data were collected from family members. A next?generation sequencing method was applied to screen possible mutation sites, and Sanger sequencing was performed to determine pathogenic gene mutations. Dermoscopy was conducted to observe skin lesions in the patients with XLDPP, and the Fotofinder system and very high frequency (VHF) ultrasound system were utilized to assess the severity of photodamage. Liver and gallbladder ultrasonography as well as blood examination were performed for all the family members. Results A deletion mutation, c.1706?1709ΔAGTG, was detected in the ALAS2 gene on the X chromosomes of all the patients in this family, which led to replacement or loss of 19-20 C?terminal residues through transcriptional frameshifting, and eventually caused an increase in ALAS2 activity. In the patients with XLDPP, skin photodamage was relatively severe;protoporphyrin?induced hepatobiliary damage was observed and aggravated with age;anemia and iron deficiency occurred sometimes. Conclusion The deletion mutation c.1706?1709ΔAGTG of the ALAS2 gene may be the underlying cause of XLDPP in this pedigree.

Retinosquise juvenil ligada ao X / X-linked juvenile retinoschisis

Relatar o caso de um paciente masculino de 28 anos que foi encaminhado ao Centro de Estudos e Pesquisas Oculistas Associados (RJ) para avaliação de retina e apresentou os achados típicos de retinosquise juvenil ligada ao cromossomo X: maculopatia cistóide com formação de cistos na fóvea e retinosquise periférica. Foi realizado o manejo conservador, com atenção para as complicações.

Report the case of a male 28 years-old patient, who was referred to Centro de Estudos e Pesquisas Oculistas Associados – RJ, to retina assessment and presented the tipical findings of the X-Linked Juvenile Retinoschisis: A cystoid maculopathy with formation of foveal cysts and schisis of the peripheral retina. It was carried out the conservative management, with attention to the complications.

Incontinentia pigmenti or Bloch-Sulzberger syndrome: a rare X-linked genodermatosis

Incontinentia pigmenti is a rare X-linked genodermatosis that affects mainly female neonates. The first manifestation occurs in the early neonatal period and progresses through four stages: vesicular, verruciform, hyperpigmented and hypopigmented. Clinical features also manifest themselves through changes in the teeth, eyes, hair, central nervous system, bone structures, skeletal musculature and immune system. The authors report the case of a patient with cutaneous lesions and histological findings that are compatible with the vesicular stage, emphasizing the importance of early diagnosis and appropriate therapeutic management.

Incontinentia pigmenti

Incontinentia pigmenti is a rare genodermatosis in which the skin involvement occurs in all patients. Additionally, other ectodermal tissues may be affected, such as the central nervous system, eyes, hair, nails and teeth. The disease has a X-linked dominant inheritance pattern and is usually lethal to male fetuses. The dermatological findings occur in four successive phases, following the lines of Blaschko: First phase - vesicles on an erythematous base; second phase - verrucous hyperkeratotic lesions; third phase - hyperchromic spots and fourth phase - hypochromic atrophic lesions.

Enfermedad de Kennedy en el Perú: Primeros casos con diagnóstico molecular / Kennedy disease in Peru: First cases with molecular diagnosis

La enfermedad de Kennedy es un trastorno neurodegenerativo de herencia recesiva ligada al cromosoma X, de inicio en la adultez, caracterizado por degeneración progresiva de las neuronas motoras espinales, debido a una mutación dinámica del gen del receptor de andrógeno. Se presentan tres familias (cinco casos) con temblor, calambres, debilidad muscular generalizada lentamente progresiva con atrofia, afectación de músculos bulbares y alteraciones endocrinas. El estudio neurofisiológico demostró compromiso de segunda motoneurona. El análisis molecular mostró una expansión anormal de tripletes citosina-adenina-guanina en el gen de receptor de andrógeno en todos los casos. Todos los pacientes cursaron con una presentación clínica típica de la enfermedad siendo los primeros casos de enfermedad de Kennedy con diagnóstico molecular realizado en el Perú.

Kennedy’s disease is an X-linked recessive disorder with onset in adulthood, characterized by progressive degeneration of spinal motor neurons due to a dynamic mutation in the androgen receptor gene. We report three families (five cases) characterized by progressive weakness involving both limbs and bulbar muscles, atrophy, tremor, cramps and endocrinologic disturbances; the neurophysiological studies demonstrated second motor neuron impairment. The molecular analysis identified abnormal CAG repeats expansion in the androgen receptor gene (AR) in all cases. Clinical features were consistent with other previous reports. These are the first Peruvian cases of Kennedy´s disease with confirmed molecular diagnosis.

Detection of TRAPPC2 gene mutation in a Chinese pedigree of X-linked spondyloepiphyseal dysplasia tarda / 中华检验医学杂志

Objective To identify the mutation of trafficking protein particle complex 2 (TRAPPC2) gene in a large Chinese pedigree with X-linked spondyloepiphyseal dysplasia tarda by the PCR-based capillary electrophoresis methods.Methods The blood samples were collected from a large Chinese pedigree of three generations with six affected persons with X-SEDT.Four exons comprising the TRAPPC2 gene open reading frame as well as their exor/intron boundaries were analyzed by argrose electrophoresis and bidirectional direct sequencing of PCR products.Fluorescence labeled fragment analysis was performed by capillary electrophoresis.Results A 5-bp deletion mutation of TRAPPC2 gene in exon 5,c.262_266delGACAT (D88del; I89fX12),was identified in the proband and his unaffected mother(a heterozygote) in the Chinese family with X-SEDT,but no other sequence change occurring in exons 3,4 and 6 was detected.The old sister of proband was determined being carriers because she carries the deletion fragment allele of exon 5 PCR product and the young sister being normal individuals because she carries the wild allele of TRAPPC2 gene.Conclusions The mutation c.262_266delGACAT (D88del; I89fX12) of TRAPPC2 gene was firstly reported in Chinese people.The mutation of c.262_266delGACAT (D88del; I89fX12) in TRAPPC2 gene may be the pathologic cause of the patients in the X-SEDT pedigree.Fragment analysis combined with DNA sequencing by capillary electrophoresis method is effective laboratory test in the small deletion mutation analysis and carriers screening in X-SEDT family.

Você conhece esta síndrome? / Do you know this syndrome?

A síndrome de Goltz é uma doença genética rara, de herança dominante ligada ao X, mais comum em doentes do sexo feminino e, na maioria das vezes, resulta no aborto dos fetos do sexo masculino. Tem um amplo espectro de manifestações clínicas possíveis. O diagnóstico consiste no somatório dos numerosos achados clínicos, radiológicos e histopatológicos. O tratamento é o aconselhamento genético, cirurgias reconstrutivas e abordagem multidisciplinar, com objetivo de melhorar a qualidade de vida e garantir uma vida normal e produtiva.

Goltz syndrome is a rare genetic disease of X-linked dominant inheritance. It is more common in female patients and, in most cases, results in miscarriage of male fetuses. It has a broad scope of possible clinical manifestations. Its diagnosis consists of the sum of the many clinical, radiological and histopathological findings. The treatment options are genetic counseling, reconstructive surgery and multidisciplinary approach, aiming to improve quality of life and ensure a normal and productive life.

Caso para diagnóstico / Case for diagnosis

Queratose folicular espinulosa decalvante é uma genodermatose rara, ligada ao X, caracterizada por hiperqueratose folicular, fotofobia, alopécia cicatricial do couro cabeludo e supercílios. Descreve-se o caso de paciente do sexo feminino, de 25 anos, com quadro clínico e evolução típicos desta síndrome.

Keratosis follicularis spinulosa decalvans is a rare X-linked genodermatosis, characterized by follicular hyperkeratosis, photophobia, scarring alopecia of the scalp and eyebrows. A case of a 25 yearold female with typical clinical picture and progression of this syndrome is described.

X-linked Opitz G/BBB Syndrome: Identification of a Novel Mutation and Prenatal Diagnosis in a Korean Family

X-linked Opitz G/BBB syndrome (XLOS; MIM 300000) is a rare multiple congenital anomaly disorder that is characterized by facial anomalies, laryngeal/tracheal/esophageal defects and genitourinary abnormalities. XLOS is caused by mutations in the MID1 gene which encodes a microtubule-associated RING-Bbox-Coiled-coil (RBCC) protein. We recently found a four-year Korean male patient who was suspected of having XLOS. Mutation analysis of the MID1 gene in the patient and his mother demonstrated that the patient had a novel insertion mutation (c.1798_1799-insC), and his mother was a heterozygous carrier of the mutation. After identification of the causative mutation in this family, prenatal diagnosis of two consecutive fetuses were successfully undertaken. This is the first report on a genetically confirmed case of XLOS in Korea.

X-linked Severe Combined Immunodeficiency Syndrome: The First Korean Case with gamma c Chain Gene Mutation and Subsequent Genetic Counseling

X-linked severe combined immunodeficiency (X-SCID) is a rare, life-threatening immune disorder, caused by mutations in the gamma c chain gene, which encodes an essential component of the cytokine receptors for interleukin-2 (IL-2), IL-4, IL-7, IL-9, IL-15, and IL-21. A 13-month-old boy with recurrent infections who had reduced serum immunoglobulin levels and decreased numbers of CD3, CD16/56 cells was evaluated for gamma c chain gene mutation and protein expression. The patient had a C-to-T point mutation at nucleotide position 690, one of the hot spots, resulting in a single amino acid substitution of cysteine for arginine (R226C), as determined by direct sequencing and PCR-RFLP. The patient's mother was a heterozygous carrier. Percutaneous umbilical cord blood sampling was performed at the 6-month of gestation in a subsequent pregnancy. As the immunophenotype of the fetus showed an identical pattern, the pregnancy was terminated and genetic analysis of the abortus confirmed recurrence. This is the first report of the molecular diagnosis of X-SCID in Korea. Genetic analysis of the gamma c chain gene is useful for definite diagnosis and genetic counseling for X-SCID.

Molecular Analysis of X-linked Chronic Granulomatous Disease in Five Unrelated Korean Patients

Chronic granulomatous disease (CGD) is a fatal genetic disorder in which phagocytes fail to produce antimicrobial superoxide because of NADPH oxidase deficiency. Molecular defects in CYBB gene causing X-linked CGD are responsible for about 70% of all cases. This study was done to confirm genetic defects of CYBB gene in five Korean patients who were highly suggestive of having CGD by clinical history. We performed initial screening for five unrelated Korean patients using single strand conformation polymorphism (SSCP) and then selective sequencing for the regions involving the abnormal bands. Activated NBT tests revealed that all patients were X-linked. SSCP analysis for CYBB gene showed abnormal bands in all patients. The molecular defects of five patients were as follows: c.1663insT, c.1111-1G>T, c.39_40insG, c.927delC and c.434T>C mutation. This result will help the families with prenatal diagnosis or genetic counseling.