We report the case of a 3-year-old girl with alpha-thalassemia/mental retardation linked to chromosome 16 (ATR-16) syndrome. The patient presented with hypotonia, developmental delay, and characteristic facial features including hypertelorism and a broad nasal bridge. Blood test results indicated microcytic anemia and normal iron status, suggestive of thalassemia. Genetic analysis revealed that the patient harbored a 465 kb deletion in the 16p13.3 region and a 19.4 Mb duplication in the 16q22.1-q24.3 region. The patient presented with rare complications of ATR-16 syndrome, including anal fistula, vesicoureteral reflux (VUR), and patent ductus arteriosus (PDA). Comparison of this case with previously reported patients with pure partial trisomy 16q suggested that the duplicated distal 16q region may be a critical locus associated with VUR and PDA.

Chromosome 15q duplication (Dup15q) syndrome is a rare genetic disorder that presents with a range of psychiatric and neurological symptoms. To date, no cases have been reported involving a patient with a 300 kb microduplication on chromosome 15 presenting with developmental delay, intellectual disability, attention-deficit/hyperactivity disorder (ADHD), and epilepsy. We describe a 20-year-old male diagnosed with Dup15q syndrome at the age of nine. His early development was marked by congenital strabismus, global developmental delay, and intellectual disability, which required enrollment in a special education program until age 11. He also exhibited hyperactivity, aggression, and self-injurious behavior. Since then, both his motor and cognitive functions have progressively declined. At age 14, he was diagnosed with ADHD. Treatment with atomoxetine, methylphenidate, and risperidone provided partial symptom relief. However, escitalopram triggered episodes of severe tantrums and was subsequently discontinued. From the age of 16, he began experiencing epilepsy, characterized by focal seizures, generalized tonic-clonic seizures, and absence seizures. Valproic acid (VPA) was effective in significantly reducing his seizure activity. This case highlights that Dup15q syndrome associated with a 300 kb microduplication can predominantly affect the central nervous system and may respond favorably to atomoxetine, methylphenidate, risperidone, and VPA. Dup15q syndrome should be considered in the differential diagnosis of individuals presenting with developmental delay, intellectual disability, ADHD, and epilepsy.

Background: Congenital adrenal hyperplasia (CAH) represents a group of autosomal recessive disorders characterized by impaired cortisol synthesis in the adrenal glands. Over 90% of CAH cases result from a deficiency of the enzyme 21-hydroxylase (21OHD). The clinical spectrum of 21OHD ranges from the severe, life-threatening salt-wasting classic form, often presenting with prenatal virilization in females, to the non-classic (milder) form, which lacks glucocorticoid deficiency. Females with the non-classic form may experience symptoms of hyperandrogenism or infertility later in life, while males with non-classic CAH are often undiagnosed due to the subtler presentation. The coexistence of genetic anomalies and CAH is rarely reported in the literature, particularly in cases involving Triple X syndrome-a condition typically associated with a mild and frequently underdiagnosed clinical course. Case presentation: Here, we present a unique case of a 38-year-old woman with a history of premature ovarian failure and subsequent clinical features of hyperandrogenism. Further investigation revealed a novel association between partial 21OHD and a Triple X karyotype-an association not previously documented in the literature. Conclusions: This case highlights the potential for coexisting rare genetic conditions and underscores the critical importance of thorough and meticulous clinical evaluation.

The 16p11.2 deletion syndrome is a clinically heterogeneous disorder, characterized by developmental delay, intellectual disability, hyperphagia, obesity, macrocephaly and psychiatric problems. Cases with 16p11.2 duplication syndrome have similar neurodevelopmental problems, but typically show a partial 'mirror phenotype' with underweight and microcephaly. Various copy number variants (CNVs) of the chromosomal 16p11.2 region have been described. Most is known about the 'typical' 16p11.2 BP4-BP5 (29.6-30.2 Mb; ~600 kb) deletions and duplications, but there are also several published cohorts with more distal 16p11.2 BP2-BP3 CNVs (28.8-29.0 Mb; ~220 kb), who exhibit clinical overlap. We assessed 100 cases with various pathogenic 16p11.2 CNVs and compared their clinical characteristics to provide more clear genotype-phenotype correlations and raise awareness of the different 16p11.2 CNVs. Neurodevelopmental and weight issues were reported in the majority of cases. Cases with distal 16p11.2 BP2-BP3 deletion showed the most severe obesity phenotype (73.7% obesity, mean BMI SDS 3.2). In addition to the more well defined typical 16p11.2 BP4-BP5 and distal 16p11.2 BP2-BP3 CNVs, we describe the clinical features of five cases with other, overlapping, 16p11.2 CNVs in more detail. Interestingly, four cases had a second genetic diagnosis and 18 cases an additional gene variant of uncertain significance, that could potentially help explain the cases' phenotypes. In conclusion, we provide an overview of our Dutch cohort of cases with various pathogenic 16p11.2 CNVs and relevant second genetic findings, that can aid in adequately recognizing, diagnosing and counseling of individuals with 16p11.2 CNVs, and describe the personalized medicine for cases with these conditions.

Pure partial trisomy 16q12.1q22.1 is a rare chromosome copy number variant (CNV). The primary clinical phenotypes associated with this syndrome include abnormal facial morphology, global developmental delay (GDD), short stature, and reported predisposing factors for atypical behavior, autism, the development of learning disabilities, and neuropsychiatric disorders. The dosage-sensitive genes associated with partial trisomy are not disclosed preventing to establish a genotype-phenotype correlation. We report a case of a Chinese patient diagnosed with GDD and an abnormal facial shape, who was found to have partial trisomy 16 through karyotyping and high-throughput sequencing analysis. Karyotype and CNV tracing analyses were also conducted on the biological parents of the patient to assess for any chromosomal structural abnormalities. Additionally, we included 29 patients with pure partial trisomy 16q, reported in the DECIPHER database and the literature. We and performed a genotype-phenotype correlation analysis. The proband, a 2-year-old female, was found to have a de novo 21.96 Mb duplication located between 16q12.1q22.1, with no other deletions observed on other chromosomes, indicating a pure partial trisomy of 16q. Through genotype and phenotype analysis of 29 individuals, we found that patients with the duplicated region located at the distal region of 16q may exhibit more severe symptoms than those with duplication at the proximal region; however, no relationship was identified between phenotype and the size of the duplicated segment. We report, for the first time, a patient with partial trisomy 16q validated by multiple genetic tests, including CNV-seq, whole exome sequencing (WES), and karyotyping. It is speculated that partial trisomy of 16q may be associated with continuous gene duplication. However, functional studies are necessary to identify the causative gene or critical region linked to duplication syndrome of chromosome 16q.