Congenital diaphragmatic hernia (CDH) represents a spectrum of rare developmental defects resulting from an aberrant embryonic morphogenesis of the developing diaphragm. The diaphragmatic defect allows an upward displacement of the abdominal organs into the thorax with a consecutive compression of the intrathoracic compartment, leading to hypoplasia of the lung, secondary pulmonary hypertension, and intestinal malrotation [
1]. CDH occurs with a birth prevalence of 1 in 3000–4000 [
2]. Long-term complications are gastroesophageal reflux disease, failure to thrive, neurocognitive defects, and hearing loss [
3,
4]. In approximately 50–60 % of patients, CDH occurs as isolated malformation [
2,
5]; about 40 % present with additional anomalies of other organ systems, including the central nervous system (5–75 %), the cardiovascular system (4–63 %), the genitourinary system (5–27 %), and the gastrointestinal tract (1–20 %) [
6]. Among the associated genitourinary anomalies, renal anomalies are common, comprising renal agenesis, dysplasia, hypoplasia, or hydronephrosis [
7]. In the past, conventional karyotyping identified chromosomal anomalies in about 6.3 % of cases [
2]; in recent studies, researchers used microarray analysis and identified smaller genomic loci, with and without candidate genes [
1,
8]. However, the etiology of CDH is still unknown in more than 70 % of patients [
2]. In this report, we present the first case of a
de novo partial tetrasomy 4q35.2 in a father with isolated unilateral renal agenesis and isolated CDH in his son, respectively.